Sepulchrave mentioned the alarm as a possible drain source. 

 

Trouble is, its an  aftermarket unit  installed by the  main dealer and doesn't show on VCDS scans - without pulling the dashboard to pieces I don't know where they have put its control box or what circuit they've piggy-backed it on.

 

Are there any usual candidates for this ?

 

Similarly, the radio is aftermarket, again installed by the deale,  and I'm not sure which circuit they connnected it to.

 

I did measure the draw at the fuseholder for  the audio/navigation circuit,  yesterday, but it showed no ampage or voltage.

 

I'll dig out the documentation on the alarm to find out how to turn it off (and on again after I've measured the drain) and same with the radio.

 

 

Whatever is causing the excess drain it seems to be there and then not there every couple of seconds causing variation between 0.25 and .45 amp.

 

Nick

Get rid of that alarm. Top priority.

Alternative and far cheaper idea. Have you tried a solar battery charger you can have permanently in situ like on a rear window or something ?

 

It might keep a trickle that is enough to keep the other demands at bay a bit, certainly wouldn't hurt to try and they aren't expensive and can be handy to have, and cost nothing in electricity.

 

Okay probably leading to bad time of year to be any use, but reviews on them seem to be positive. I've got one in place for topping up my bike battery through a window in the garage.

I think if you look back that has been considered, but consider this, what physical size of solar cells would guarantee you 0.5Amp in the worst day and as day light can be as low as 8 hours or so in winter, he would need something that would give nearer 1.0Amp minimum to keep that battery up. In my very limited experience of solar chargers, that would translate into something handing out 10Amps (a guess) in a sunny day - no can do!

Get rid of that alarm. Top priority.

 

Different car, 2009 Ibiza, but any idea if VAG include a rechargeable battery into their alarm sounders, I've read that Audi did and lots of these rechargeable batteries needing replacing - though maybe it did not mean that a faulty rechargeable alarm battery discharged the car battery when the car was left locked up. Personally I've had a 2000MY Passat for 13 years and a 2003MY Polo for 13 years without any alarm issues - ie no duff batteries if indeed they had alarm batteries.

Alternative and far cheaper iob . Have you tried a solar battery charger you can have permanently in situ like on a rear window or something ?

 

It might keep a trickle that is enough to keep the other demands at bay a bit, certainly wouldn't hurt to try and they aren't expensive and can be handy to have, and cost nothing in electricity.

 

Okay probably leading to bad time of year to be any use, but reviews on them seem to be positive. I've got one in place for topping up my bike battery through a window in the garage.

Already gone down that route. The solar cell I was using was rated at  max 4W i.e.300 ma @ 12 v. It wasn't producing anything like that even in direct sunlight. Certainly not enough to match the background drain of equipment in sleep mode + natural wastage of the battery which, as i have said ,draws between .25 and .45 a.

 

My researches indicate that I'd need a solar cell rated at max of at least 100w to be able to meet the demand on an overcast day when you could expect no more than 15% of max rated output from the solar cell. Only a half metre square cell (l 1.2 metre s long x 0.5 metre wide), of the type they use for recharging caravans leisure batteries are rated for max 100w output - might be a bit problematic fitting that on the parcel shelf, let alone the cost - the lightweight flexible  monocrystaline cells of that type weigh-in at £130 +.

 

Its the size of the battery drain that's wrong. 

 

Thinking about it, the battery current drain readings I have taken to date have been with the alarm and all other services off and all the doors and windows closed but not locked (Through central locking).

 

The question is whether the alarm is malfunctioning in its own sleep mode and is intermittently drawing current in bursts. And the only way I am going to determine that is establish which circuit the dealer has connected it to and either pull the fuse (if its the sole consumer on a circuit) or disconnect the alarm box. But I'll have to find the alarm control box first and be able to identify the wiring from the colour/connection. Possiible locations for the alarm control box are  either behind the Glove box or near the relay and fusebox by the driver's  right knee position.

 

Interestingly, there are a couple of additional thin wires attached to the car's battery leads and I wonder whether these are for the alarm as obviously it must bypass the ignition switch for its power. That said there are at least 5 other circuits that i have found that bypass the ignition switch.(Horn, starting and charging circuit (Unlikely to be chosen as the  power source because of spikes), cigarette lighter, heater blower, front windcreen washer pump, and rear fog lights (Probably all of these can be discounted because they are two high a draw)

 

After reading the alarm documentation, I'm just hoping there's no immobiliser function built into the alarm as  I understand, if I've read it right,  that  the alarms immobiliser function may prevent the car from starting or reduce its fiunctionality when the box is removed - It appears that this particular range of aftermarket alarms has an immobiliser assist function which supplements Skoda's own on-board immobiliser.

 

I might deploy the infra red point and shoot temperature sensing gun - it might be quite good in this cold weather in detecting electrical hot spots in the cabin or under the bonnet.

 

N

Edited 15 October, 20169 yr by Clunkclick

"I might deploy the infra red point and shoot temperature sensing gun - it might be quite good in this cold weather in detecting electrical hot spots in the cabin or under the bonnet."

 

Hum, the above normally works okay with commercial/industrial badly maintained/faulty switch gear and junction boxes etc - but I'd doubt if it would see much in that car!

No harm in trying - I'd say that a component e.g  a shorting temp flap motor, that's consuming half an amp at a high frequency intermittance would become a bit toasty.

 

I was using it last year to do spot skin tests on various potential  Lymphoma related swellings across my person and, at close range, it could easily differentiate between "Active"  areas  and "Inactive" down to tenths of a degee C over the body temperature range 32-37 C. Very effective.

 

Nick

Not looking too good:-

 

Wednesday  12/10/2016 -   Battery voltage 12.9

(After 60 mile round trip)

 

Friday  14/10/2016          -   Voltage   12.42 volts (In between 0-25% discharged)

                                    CCA       560 EN

                                    SOC:        78%

                                    SOH         77%     

 

 

Friday, again, after T/O       Voltage     13.08 volts (Fully charged)

 engine for 10 mins             CCA          568 EN

                                            SOC          100%

                                            SOH             78%

 

 

Today, Monday 17/10/2016 Voltage   12.05 volts (In between 75 -100% fully discharged)

                                             CCA        472 EN             

                                             SOC       31%

                                             SOH        65%

 

 

So, in three days of disuse its lost 70% of its charge and 13% of its capacity.

 

 

Ambient temperature is 12 C

 

 

Guinness book of records ?
 

For students of "Normal" that isn't, surely ?

 

 

 

Nick

Edited 17 October, 20169 yr by Clunkclick

Well, in my case the late 2009 Ibiza 1.4 SC 85PS with a similar sort of problem:- postie delivered a letter from my local (preferred) SEAT dealership - "we are closing on 31st Oct" - so as there is some maybe unfinished business there with that car, I've left it with them today to find out why the original fix (£460) three months ago only sorted it for a couple of months.

 

The only reason that dealer is closing is that they are located in town in a very desirable (for quality housing) area and that car parking is becoming impossible - they support, SAAB, SEAT, Alfa Romeo, Suzuki all at one very small site, which is a pity, SEAT will do nothing to find a replacement as Uncle Arnie's car emporium is the local main dealer for SEAT in my area and I'd rather give them a miss if possible! I've been advised that SEAT UK will get in touch to help introduce me to Uncle Arnie!

Perhaps, a substantial part of the reason that you weren't getting the level of service you expected over the last few months was the fact the dealership was teetering.

 

If you are referred to somebody else, lets hope they are sound.

 

Concurrent Joint franchises is what appears to be done in a lot in provincial dealerships - an lets face it, there must be a fare scope for that as regards the various VAG marques. 

 

Most of the parts in Skoda Fabs are common with the Mk 6 Polo - they even have the same battery drain problems.

 

I wouldn't be surprised over the next few years to see a trend for dealerships tied to manufacturers to disappear, for car sales to go mainly on-line and for servicing to be done by manufacturer independent facility management companies - per that City of London inspired trend in other sectors.

 

Unfortunately,  the practice of taking consumer expenditure up front, failing to render value and then denying consumers the facility to recover those unexpended funds, is nothing new in the UK over the last 30 years and certainly not exclusive to the motor trade - the nubile phone companies probably being the leading exponent of the art - think PAYG simms.

 

My situation is still unresolved. 

 

There is, quite clearly, a substantial drain on the battery when the car is unused.  The battery charge was reduced to 30% (From 100%) in three days whilst the car is at rest. So on Tuesday, I removed it, to prevent sulphation and possible damage. Since then, its been on charge. And until, I find the drain, its going to remain out whilst the car is unused and I'll just re-install every  time I need to use it (Once a week or less).

 

I think the focus of my testing will in future be on the cable connecting the battery with the alternator, the aftermarket alarm and radio installations (Which are usually the culprits 80% of the time) and the failed cabin heat situation. That's going to be next week, as parts of the dash will need to come out to resolve the last two issues.

 

If the EMU electronics will allow it, my inclination, should either the temperature flap motor or the AC  control unit (In the centre dash console) prove to be unserviceable, will be to remove and not replace them - the dealer  provided replacement costs (Labour and parts)  are respectively £70 and £198. In that situation, the heat, sans blower, can be restored using this cheap-as-chips ingenious solution - 

 

 

 

Nick

Edited 20 October, 20169 yr by Clunkclick

Well, I've conatcted my SEAT dealer to find out what they have discovered with the late 2009 Ibiza 1.4 SC that I handed back in to them with a recurring battery drain problem. They have had the car since last Wednesday, though probably only started checking it over on Thursday. First time round, back in May>June this year they found that it was the steering sensor underneath the steering wheel that was causing the bus lines issues so wakening up certain supplies when the car was parked up - and replaced that. That seemed to make thing better for a couple of months then it was back to failing to start due to discharged battery if left more than 5>7 days. This time, they have found no abnormal current draw during "off" periods - ie NFF!

 

Now that is not too handy as it does not explain why I find it has discharged its battery after 5>7 days and if monitoring the (connected) battery voltage daily over 7 days I can see that the battery voltage is dropping quickly, which supports the "flat battery" situation when trying to start the car after that period.

 

So, I'll have a word with the tech and see what he suggests I do myself as it looks like doing things the VW Group dealer approved way is that yielding any suspect problems - and the customer still ends up with a car that will probably not start if left 5>7 days - not good!

Well no good news after visiting the dealer who closes their doors 31st October, all they gave me was a receipt for "diagnose repeat of battery drain situation - current draw checked and no abnormal drain found" cost £0.00, and all they could offer me was SEAT's UK customer direct line who could give the necessary authorisation for further investigation at another dealer as I was a "loyal customer with almost complete SEAT dealership history" - last service was done by me due to dealer being closed too long (for me) over the festive period!  Today, unfortunately due to other commitments I arrived at the dealer too late to chat with the tech - but he reported to the service manager that he remembered working on this car back in May/June and confirmed that at this moment in time, there is no abnormal current drain - so no fault to investigate!  Which if that is what he found I do respect having been a test engineer for too long!

While the service people accept my frustrations, they can not provide me with any more technical back up as this operation is cruising into closure - I certainly can not blame them for acting like that as I have been in an "operations closure" situation twice in my working life, though, as all that dealership's team, moved on to other sites.

One final check for me before trying to get SEAT to check and if necessary apply a software patch to the BCM management software, is to disconnect the battery and check it over a 7 or more days period for discharge/open circuit terminal voltage drop. To that end, I've removed the earth lead, fitted a long monitor lead across the battery and manually locked both front doors.

That's exactly what  I have been doing with my new battery.

 

Taking it out of the car, charging it up on a C-Tek Mx 5.0 and then leaving it to stand to see if there was any fall-off in the state of charge.Repeatedly, nothing found. 100 % state of charge (According to the Foxwell Battery Analyser) when it was taken off charge every evening and, it still showed, 100% the following morning.Ditto the voltage @ 13.1 volts (Loads of surface charge  just after being taken off charge) in the evening and 12.8 volts in the morning i.e. that equates to 100% charge in both cases. The charge/stand cycle was repeated for 6 days  in a row.

 

And you recall that I already did a "Homebrew" 100amp load test on the battery over 30 seconds and its state of charge only diminished by a couple of percent (Whereas its predecessor  lost 20%). 

 

 I installed it back into the car On Monday. Used the car Monday, no problems for a 12 mile return journey. And a plug in voltmeter inserted into the cigarette lighter socket read 13.1 volts. So apparently fine.

 

Untypically, went to use the car today and the voltage (Taken through the cigarette lighter socket) was 12.2 Volts. That's in the region ojust over 50% charged. So in two days of none use its lost 50% of its charge. And the ambient temperature has been about 16 C all week. 50% loss-of-charge equates to 31.5 amps on a 63 amp hour battery. 31.5/48 =  0.66 amp per hour loss of capacity. As you recall the loss I have measured from the negative terminal of the battery, ignition off, services off, doors closed, alarm varies between 0.25 -0.45 amp. 

 

Erwin/Elsa documentation, previously published on another thread on this site, states that, even for the VRS, the static drain should be no more than 0.045 amps (45 milliamps).

 

Just to make sure the battery is not the problem, I got myself a C- Tek MX 10. This is capable of deliverying 10 amp max. Interestingly, on first use today, I applied it to the Varta predecessor battery. This had been on charge all day, using the C-Tek MX 5.0 charger (5 amp max) and was by mid -afternoon, when i disconnected it,  showing stage 7 (Green light), fully charged. After letting the battery stand for 15 minutes, i attached the MX 10 and this immediately started charging from stage 4 , absorption, and continued until mid-evening when it reached stage 7 again.

 

My theory, is that charging these batteries is rather like formattting a  computer hard disk. If you change an ageing computer power-egg for a new one, the new one knocks out a slightly higher voltage and renders any disk formatted when the old power supply was in place as unreadable. Similar with the batteries, except I'm convinced  that the more wattage per unit of time put in during charge, the deeper the charge is and the more power gets stored. The proof of the pudding is when I test the state of health parameter on the  predecessor battery tomorrow, using the Foxwell battery analyser. To date the predecessor battery has been showing 100% state of charge, 78% state of health. Perhaps the state of health %age will increase further towards 100 ? We shall see.

 

It would be interesting to know what ampage and voltage the battreies were charged at before leaving the factory and whilst sitting on the shelves at the distributors (If at all).

 

Most of the authorities say that a battery should be charged @ 10% of its full capacity for the first 5 hours if it is to achieve "First base"  i.e.70% charge. We are told that it should then take double that time to charge the remaining 30% of capacity at a lower wattage before reaching 100%.

 

However, using the MX-5 to charge the old Varta and Bosch 63 amp hour batteries, there was only a maximum of 5 amps that could be supplied i.e. less of 10% of the total capacity of the battery. So my feeling, is that the batteries haven't really been getting a full-charge. What's more, the MX-5 has been getting very hot when charging either of these batteries at stages 3 & 4, bulk and absorption mode. So much so, that I've had a fan playing on it for cooling purposes. MX -10 has been running cool all the time.

 

Changing topic, this evening, my suspicions were confirmed re the cabin heat failure. With the engine running and  the headlights on, none of the illumination on the switches or the dials for the heater/air conditioning console in the dash came on (You recall that I previously suspected that fresh/recirculated air flap motor had failed). Now I'm suspecting that the circuit board behind these switches and dials, or at least part of it has failed or one of the fuses has failed (Fuse f12, 5A).

 

The left hand side of this board is powered by the circuit coming out of Fuse 12. This circuit  supports an electronic control unit which also seems to power the fresh/recirculated air flap as well as the total illumination on the console. All of the services running off the left hand side of this board via the electronic control unit have failed.. Whereas the right hand side of the board, which runs off of a separate circuit via Fuse 68, 25A, houses the blower switch. The blower is operating fine, so one concludes that the blower switch and resistor pack (Which provides the different blower speeds) are fine. 

 

So if Fuse 12 and connected wiring test OK tomorrow for continuity and insulation, then suspicion will fall on this heater console board and perhaps on the flap motor as well.

 

As to the heater circuitry causing the drain, only the blower circuit (Fuse 68), because of its high ampage, bypasses the ignition switch. However, the circuit is switched by a solenoid (X -contact relay 18) on another circuit ( Unfused, except at the battery lid) running off of the ignition switch and feeding, along with  the supply from the blower switch, the blower motor. If all in this circuit is functioning properly, the blower can only function when the ignition is switched on. However, if relay 18 is stuck on, the blower may receive power and whilst, the power delivered is insufficient to turn the blower motor, it may drain through it to earth. It's a longshot but I can test for it tomorrow.

 

If the heater console board has gone, ifrom my web researches thus far, its going to be near impossible to get a new one. So, it may well be that it gets left in place whilst the blower is still working and the cable tie solution is adopted. I note that third parties are selling patterned flap motors for £71 - £151, take-your-pick. That cable tie looks attarctive !

 

Subject to the testing I will be doing tomorrow, I'm still not convinced that the heater is causing the drain. 

 

A new set of multimeter leads arrived at the beginning of the week enabling me to test the small fuse holder sockets for current and voltage. So I'll be doing all the small fuses tomorrow

 

Additionally, I'll be testing the lead from the alternator to the battery +ve terminal for AC voltage as I understand that, with the engine running and alternator turning, this is a surefire way of testing whether the alternator diodes have gone - allowing a drain ftom the +ve terminal to earth through the alternator when the engine is off.

 

 We shall see what occurs on all fronts tomorrow !

 

Nick

Edited 27 October, 20169 yr by Clunkclick

As regards electric/electronic faults, the same items and modes of failure crop up across the the VAG group.

 

 For instance Polos, Golfs. Arosa all have the same problems with the kittening heater/air con controls.

 

What's more, it goes across the marks of each type i.e. its longstanding historical problem And,VAG ar e so kitten idolent that they have done NOTHING about it. You've only got to look at E-Bay at the serried ranks of second-hand heater controls on offer as replacements.

 

How is that for "Sod the customers" ?

 

Quite honestly, looking at the fault diagnosis procedures used by VAG, as downloaded from Elsa, Erwin et al, they are so dumbed down and procedural i.e. "Take VAG tool XXXX, set tool to DC volts, apply to terminal T of component X, start the engine, if value is > 5, go to procedure 2, if not replace part", it doesn't leave the testing technician much room for inspired hunches or the use of experience as you'd find in a franchise free  auto electric shop.

 

So, on two counts, any wonder problems don't get solved.

 

 

Nick

Edited 27 October, 20169 yr by Clunkclick

Whilst the drain fault on mine is ongoing, I think I'll try running a two battery system using the predcessor battery, swapping then

m over  only when the installed battery gets down to 30%  (4 days) and then wacking it on the MX 10.

 

But as you've indicated, the speed at which both your and my batteries are draining  to flat seems to be the same i.e.one week

 

If I were a betting man, I would put money on the possibility that the same component is involved.

 

I'd further bet that the issue is well known to VAG ( And some of its dealers)  and that, rather like the "Sealed-for-life" gearboxes (Hah !) owning up to it is verbotten on pain of loss of franchise/Ceo job  (Again take your pick).

 

The only way to identify this is to pull fuses selectively, one at a time, starting with the link fuses in the battery lid and leave the vehicle for a 3-4 days on each occasion to see what happens. I have 40 fuses in, so if i don't get lucky, that could take until summer next year, although, on examination, it may be possible to pull multiple fuses per occasion, where the circuits are not cross linked.

 

I think I may start with just disconnecting the ECU.

 

Also, the act of disconnecting and re-connecting may cure the problem, as, on my reading, a lot of the intermittent faults are caused by corrosion on the pins of the crappy VAG electrical plugs and sockets.

 

Clearly, the dealerships don't have the vehicles long enough on each inspection/testing to do all of this.

 

Earlier VAG marques didn't have any of these problems. It is the continual drive to get cheaper (Crap) sub component prices allied to inadequate Acceptance Quality Control by the buyer that causes this.

 

Their reputation in the home country is shot already.

 

 

Nick

Edited 27 October, 20169 yr by Clunkclick

Well, "link fuses on top of battery" - well in the case of the late 2009 Ibiza, things have advanced a bit, what you get is a "multi fuse link" - ie all these fuse links on one L shaped bit of metal! Now, I think tha tI need to get hold of proper schematics for this car as Haynes etc have not touched it yet and SEAT seem to do there own thing, so buying an early 6R Polo Haynes book might not be too handy - though I might weaken and go down that route, if only to find out which link fuse covers what - that was going to be part of my final discussion with the tech that had worked on that car, but I fully understand that on the final days at that job he might not be too bothered about my problems.

 

Alternator leaking back, it is easy to get the O/P lead off, just pick off the black plastic protective cap and find a maybe "13mm" nut below it and stuff that in the normal plastic bag, and if you feel to need to tick that alternator off as being part of the current drain, unclip the control/management connector.

 

On the subject of flap motors in general, I think that I've written this before, but maybe it was Tech1e that suggested once a year running "basic settings" on the AC system as that drives all the flap motors over their full range of travel and might just keep the feedback pot tracks a bit cleaner and reconfirm their endstop voltages.  I know from experience, with the auto AC systems in any of our cars, nothing gets moved much over the life of the car wrt most of these motors, so it will only be the temperature motor that will get moved by the controller slightly to maintain the cabin temperature and the recirc motor every time reverse is selected on most cars.

Ambient outside temperature down here today was 15 C and has been for the last couple of days.

As it wasn't raining I decided to venture outside and do some circuit readings on the fuse box to determine which were activewhen the ignition switch was off.Started with Fuse nos 1 -16 (Fuses F5,F8, F11, and F14 not being installed).

Battery voltage was 12.2 volts - down from the 13.4 volts on completion of a25 mile round trip when it was last used on Wednesday.

With the ignition switch off, the following circuits/Fuse numbers were active:-

F1 - Instruments/ESP - 11.10 volts

F3 - Diagnostic/ A/C - 9.90 volts(?)

F4 - Interior Lights - 7.7 volts(?)

F10- Accessories (Ciggy) - 11.90 volts

With the ignition switch on, the following circuits/Fuse numbers were active:-

F1 - Instruments/ESP - 0.60 volts (?)

F3 - Diagnostic/A/C - 10.60 volts

F4 - Interior Lights - 6.8 volts(?)

F7 - Power Steering -12.20 volts

F9 - Oxy Sensor -11.90 volts

F10- Accessories(C/L)-11.40 volts

F12 -Fresh/Recirc Air-11.90 volts

F13 -Reversing Lights-12.20 volts (Obviously only occurs when reverse gear engaged)

F15- Wash/Wipe - Zero volts when the stalk is in position 0, 3.6 volts in position 1 and 3.1 volts in positions 2 & 3.

F16- Instrument Cluster - 12.0 volts#

Just in case anybody asks, the battery in the multimeter being used for these readings, was checked yesterday @ 60% of capacity and the leads plugged between the multimeter and the fuses were of the Maplin type which had an in-line holder to accomodate the car fuse extracted. So, both the fuse and the circuit were tested simultaneously.

Well, some pretty odd readings there. Perhaps I'll revisit some of those tomorrow before going on.I don't know whether there is any virtue in checking Fuse F6, Headlight levelling, as I presume that this would require theheadlight position thumb wheel to be rotated whilst the headlights are on.

Wonder if the interior lights voltage is being pulled low by a malfunctioning aftermarket alarm. I understand that fitters usually put the main alarm power supply on the interior lights circuit.And I have been having intermittent issues with the courtesy light. According to one Golf web site I have read the alarms of the same manufacture are infamous for draining the battery and this usually happens because they haven't been fitted properly. It was suggested on this web site that fitting of this alarm should be done with two relays, rather than one, so as to avoid the drain problem. So that's one issue I'll try and take upinitially with alarm manufacturer.

Edited 29 October, 20169 yr by Clunkclick

The fact that you are measuring voltages rather than currents suggests that you may be attempting to follow the VW pdf I suggested?

The numbers you're getting, and mention of some Maplin widget and extracted fuses suggests that you've missed the point and are doing it wrongly.

 

The idea is to leave the fuses where they are at all times, and put the meter probes on the little exposed bits of metal either side of the middle bit (see pink arrows below). The numbers you get should be mV, not V,

 

 

 

Apologies if I've misunderstood your intentions.

I resorted to measuring voltages in order to protect the in car kit and the multimeter. And Erwin relies on this  measuring method in its Fault finding section.

 

I was using this:-

 

http://www.maplin.co.uk/p/900mm-car-fuse-adapter-lead-set-mini-blade-n51cy

 

You extract the fuse, insert it into the holder located on the black wire side of the device (Thus the fuse bridges a break in the black wire), then you stick the moulded lead ends into the multimeter and the metal prongs into the empty fuse holder in the car's fusebox.

 

So, essentially, when the multimeter scale is turned to volts, you get a reading in series of the total voltage going through that circuit in whatever state its in. Hence my high readings. 

 

All it is really, is detection of which circuits are live and under what conditions.  As a first stab at the problem, I was hoping to find a "Live" when there shouldn't have been.

 

Your method suggests a voltage measurement in parallel, hence the lower value ?  Can the values obtained be compared with reference values, such as might be tabulated in ERWIN or similar.

 

Out of interest, who recommends this microvoltage method. Is one of the reasons its done this way so as to protect components from potential high voltages from a failed component ?

 

I'm currently on ERWIN and printing to PDF the whole electrical system for my vehicle (Using the VIN as the database filter). Whilst the Fault Finding section lists methods, output values (In VOLTS) and algorhythms for a number of electrical components, at first sight it doesn't look comprehensive and I certainly haven't seen a reference table for Microvolt values for measurements across each fuse in the fusebox. Is there one ?

 

 

From my recent researches, ERWIN states that any measurement of  a component, switch, connector or wiring  under 11.5 volts on the system is dodgy and non-compliant.

 

Nick

Edited 29 October, 20169 yr by Clunkclick

I resorted to measuring voltages in order to protect the in car kit and the multimeter. And Erwin relies on this  measuring method in its Fault finding section.

 

I was using this:-

 

http://www.maplin.co.uk/p/900mm-car-fuse-adapter-lead-set-mini-blade-n51cy

 

You extract the fuse, insert it into the holder located on the black wire side of the device (Thus the fuse bridges a break in the black wire), then you stick the moulded lead ends into the multimeter and the metal prongs into the empty fuse holder in the car's fusebox.

 

So, essentially, when the multimeter scale is turned to volts, you get a reading in series of the total voltage going through that circuit in whatever state its in. Hence my high readings. 

 

All it is really, is detection of which circuits are live and under what conditions.  As a first stab at the problem, I was hoping to find a "Live" when there shouldn't have been.

 

 

Your method suggests a voltage measurement in parallel, hence the lower value ?  Yes Can the values obtained be compared with reference values, such as might be tabulated in ERWIN or similar.

It's a VW group method, rather than mine, directly from the technical bulletin I linked you to. There's a matrix/table of millivolts read by the meter to milliamps flowing through the fuse in question (last couple of pages of the pdf)

 

Out of interest, who recommends this microvoltage method. Is one of the reasons its done this way so as to protect components from potential high voltages from a failed component ?

VW recommend it (mV is the abbreviation of millivolts, not microvolts) . The justification is as stated on page 3

 

"Due to the state of the CAN Bus communications in the vehicle, it is no longer acceptable to pull each individual

fuse one at a time to try and identify which circuit is consuming current. Removal! reinsertion of a fuse while

vehicle is in a sleep state may wake the bus of the vehicle. and invalidate the test. Identifying "consuming" circuits

must be done by measuring a voltage drop across fuse and aligning with the value in matrix located at end of this

document."

 

 

I'm currently on ERWIN and printing to PDF (the whole electrical system for my vehicle (Using the VIN as the database filter). Whilst the Fault Finding section lists methods, output values (In VOLTS) and algorhythms for a number of electrical components, at first sight it doesn't look comprehensive and I certainly haven't seen a reference table for Microvolt values for measurements across each fuse in the fusebox. Is there one ?

 

 

From my recent researches, ERWIN states that any measurement of  a component, switch, connector or wiring  under 11.5 volts on the system is dodgy and non-compliant.

 

Nick

A couple more things.

A while ago in this thread you mentioned that your alternator output was only 13.5V at idle after a journey. That's odd, unless you had everything electric in the cabin turned on full at the time.

Suggests to me that all is not well with the alternator, its cabling, or both.

 

A simple method of disconnecting the alternator (to help rule it in/out of your battery drain investigations), is - with a 10mm socket - to disconnect the wire where it feeds into the battery fusebox, labelled "Alt" in the picture below. (Ignore the other pink stuff on the right, that pertained to another discussion). 

 

*I would suggest leaving a prominent note on the driver's seat reminding you to re-connect it before starting the engine*. I don't think it's a good idea to run the car with alternator unconnected.

 

Thanks for all the above.

 

In fact, on return from my last journey, I did attempt to measure alternator output - although not for pure generation purposes (Alternator drive belt looks nice and tight).

 

I did it to try and establish whether there is an "At rest"  drain path from the battery back to the alternator - the hypothesis being that faulty diodes in the alternator rectifier module would cause this to happen. The multimeter was set to AC volts and the leads applied across the battery terminals whilst the engine was running. Result was a voltage of 0.015 AC volts. I understand this is OK.

 

Various details obtained from ERWIN are proving to be useful - the full vehicle specification, which amongst many other things, i.e.  current flow diagrams, fault diagnosis and repair procedures, tells me that a 90 amp alternator was fitted and provides the layout and function of the link fuses in the battery lid.

 

 

Nick

Edited 30 October, 20169 yr by Clunkclick

Right.

 

Car last used Friday evening when the readings were (One hour after returning from a 36 mile round trip):-

 

Battery Analyser

13 volts

CCA 593EN

SOC 100%,

SOH  82%

 

 

Fluke MM

Drain (Measured at - ve battery terminal 0.14 -0.28amps

 

 

So, this evening @ 19.40, after two days of sitting idle,  with the car at rest, all services off,  the readings were:-

 

Battery Analyser

 

12.18 volts

CCA 546 EN

SOC 48%

SOH 75%

 

Fluke MM

Drain (Measured at -ve battery terminal was 0.72 amps, steady

 

And the ambient temperature is about 6 C lower than Friday ' 9C.

 

So, the  new Bosch battery has lost 52% of its charge and about 8% of it cold cranking capacity (@ zero C) 

since Friday.

 

And the drain rate seems to have doubled !

 

I  also tested the voltage across the battery terminals in various states  getting the following:-

 

Engine running  . . . 14.2 volts 

Engine running + headlights on main beam . . . 14.0 volts.

Engine running + headlights on main beam +  heated rear window . . . 13.9 volts.

 

Ran the engine for about 5 minutes with everything on, blipping the engine revs occasionally - no change in the brightness of the main beam with engine revs. 

 

According to chassis specific details I downloaded from ERWIN over the weekend, the alternator is rated at 90amps. There were no odd noises coming from the alternator  i.e. bearings and the belt is in good condition and well tensioned (You only depress it 1 Cm before meeting substantial resistance).

 

After switch off I took final battery analyser and drain values before removing the battery for a re-charge in doors:-

 

12.75 volts

CCA 570EN

SOC 100%

SOH 78%

 

 

Fluke MM

 0.15- 0.31 amps

 

Odd that the drain has now settled down to  the usual value i.e. under half its value at the start of the evening session.

 

I've now got the battery on charge (Reconditioning mode first), in the house,  using the C-Tek MXS 10 for the first time.

 

Its been on nearly 45 minutes so far and the 10 amp C-Tek is still on stage 3 (Bulk charge) and even this is now quite warm to the touch. So clearly, despite the last reading taken on the  Foxwell battery analyser,  its still in need of charging.

 

Plan is to fully charge the battery today and tomorrow and then re-instal it and disconnect the alternator link fuse from the battery and leave it for 48 hours to see what happens. I think, before I do that, I'll get a spare link fuse because after 13 years of use its bound to crack when I take it off. 

 

Incidentally, anyone know, how warm the heated rear window should get. Whilst it cleared the condensation, it wasn't exactly warm to the touch.

 

Nick

 

 

 

 

 

 

 

 

 

 

 

 

 

Edited 31 October, 20169 yr by Clunkclick

You don't really need to touch the fuse, just unbolt the wire from it, and stick a bit of paper/card under the crimp to stop it touching the stud.