Total Electric Failure

[Morgan621]

My 2006 Skoda Superb 1.9 TDI keeps losing power. Battery si fully charged and the car starts fine, runs well but the following day there is absolutely no power to the ignition. I have had the car at an Auto Electricians and they can't find problem. When the power is there no problems, all electrics work. I occasionally get the doors locking / unlocking whilst driving and the next day no power at all. The alternator has been checked and is ok. Anyone come across this problem before and knows how to fix this?

[Nackuk]

Is the battery Okay, is it old?

Are the battery terminals on properly?

[Danny 57]

Check main Earth battery to body connections.

[bigjohn]

Is the battery OK? - It's at this time of year they fail, sometimes not able to hold a charge overnight

 

Did the auto electrician check current drain with everything turned off?

 

 

Re the door locks opening and closing - is it wet under the passenger footwell carpet - see pinned issue for the Superb I re "water ingress"

Edited 7 February, 2016 by bigjohn

[Morgan621]

The battery is new and holds charge. There was damp on the floor and has been dried but could be wet again.

The battery terminals were renewed by the auto electrician.

They did computer runs and found nothing.

[bigjohn]

The battery is new and holds charge. There was damp on the floor and has been dried but could be wet again.

The battery terminals were renewed by the auto electrician.

They did computer runs and found nothing.

 

You must check:- http://www.briskoda.net/forums/topic/152490-water-ingress-problemsolved/

This is a really common problem with the MK I Superb (and Passat of the same age) and if not resolved you have a heap of trouble ahead. There are electrical components that get wet and damaged when the pollen filter seal leaks and when the plenum chamber drains becomes blocked (this also can rust out the brake servo!)

 

Disconnect the battery and stick an ammeter on it with everything turned off checking for current drain - this may also be related to the above

Edited 7 February, 2016 by bigjohn

[Morgan621]

I have just disconnected the battery by taking off the earth terminal and the battery is fully charged but is still not getting power to the ignition. Although I do not know anything much about car electrics,, I do know electricity. My assumption is that there must be an intermittent connection or "dry" joint somewhere. What I believe is that I have a sticky relay somewhere but do not know where to look. If I get a 'jump' from my neighbour's van, it will get power to the ignition and runs OK for a while but with the doors clicking closed / open whilst driving also suggests a faulty relay. Does anyone know of this problem or is this systematic of the filter seals leaking causing the plenum chamber problems?

Edited 8 February, 2016 by Morgan621

[bigjohn]

I have just disconnected the battery by taking off the earth terminal and the battery is fully charged but is still not getting power to the ignition. Although I do not know anything much about car electrics,, I do know electricity. My assumption is that there must be an intermittent connection or "dry" joint somewhere. What I believe is that I have a sticky relay somewhere but do not know where to look. If I get a 'jump' from my neighbour's van, it will get power to the ignition and runs OK for a while but with the doors clicking closed / open whilst driving also suggests a faulty relay. Does anyone know of this problem or is this systematic of the filter seals leaking causing the plenum chamber problems?

 

If the car starts when jumpstarted but not just on battery surely this proves you have a battery issue. Jump starting is applying voltage to the same battery terminals the only difference is the voltage is applied to the battery terminal/cables from an external source.  

This is presuming that the jump leads are being applied to the battery terminals - If the black terminal is being attached to metal elsewhere on the engine/body then your battery earth attachment has failed - surprisingly common with vibration / heat etc..

 

Edit - the more I think about it you probably have a battery earth or live cable failure. Check at every end of the cable - can't remember on the Superb but check where the earth connects to the car body and onwards to the engine/starter. The thick cables are usually crimped and become oxidised and eventually mechanically fail with vibration although they can look OK. Try connecting a jump lead between the negative "-" terminal and the engine. If an earth terminal is failing then it possibly might be making and breaking circuit with the vibration/bumps of driving

Edited 8 February, 2016 by bigjohn

[Morgan621]

After trying to work this out for ages, I have bit the bullet and taken it to a Skoda Dealer, and they have come across this problem a few times and can fix it.

Touching lots of wood in the mean time.

Thanks for your help anyway, I do appreciate it.

[Tdi1.9]

When they have fixed it, please let us know what it was.

[Morgan621]

I will let you know what the problem was. The Service Manager told me that it was probably the panel in the Ignition system. He said that when the jump leads from another vehivle was connected, the panel recognised the increase in capacity and starts the car. I will await the results when it is fixed.

[Danny 57]

I will let you know what the problem was. The Service Manager told me that it was probably the panel in the Ignition system. He said that when the jump leads from another vehivle was connected, the panel recognised the increase in capacity and starts the car. I will await the results when it is fixed.

I struggle with that explanation as they sense voltage and for the module to sense current capacity it would have to have a massive heat sink (as an ammeter is inline and requires a shunt circuit to carry most of the current) to measure the cca of the combined batteries which does not make sense but perhaps I am looking at it from a bad angle. I am basing my thoughts on when it was noted that the battery was at near 13v. Again when two batteries are used they are in not series so the voltage will only be that of the better battery.

[Morgan621]

I agree with your assesment, hence my confusion as well. I could not fathom when the battery supplies 13V and the ignition system has no lights. Yet when another battery is placed in parallel, no increase in voltage is given, yet the ignition lights come on????

As I say, I will be pleased just to get the situation sorted and I will post the results.

[oh_superb]

sounds like relay not closing, and a bit more voltage from jump battery allows it to close.  All the relays are behind the fuse box.  You need to drop the lower dash, 2-3 torx scows and down she drops.

[Morgan621]

I have visited the dealer yestrday and they had dried and re-sealed the Plenum Chamber and I witnessed them reconnecting nearly every connection in the cable runs that had choroded connections on nearly every join.

I have to pick it up later today, I await with trepidation what the bill will be.

[Morgan621]

Final bill was £450 somewhere in the region that I was expecting, although the seals have been re-done there is still a residual dampness in the car. A bit of Dehumidifying needed.

[Morgan621]

The car started no problems today. I have had a de-humidifier on inside the car for a couple of hours and it has taken most of the moisture out already.

I am planning on keeping the de-humidifier on for a few more hours, trying to get rid of as much as possible.

Thanks for all your help folks.

[Morgan621]

Furtherr to this problem, The reterminating did not fix the problem. The fault re-occurred. This time the garage said that there was an electric fault in the drivers door lock which they replaced at a cost of £230.

Guess what, this did not resolve the problem either.

I do believe that we have the correct diagnosis, in that the Convenience (comfort) ECU has a burn on the printed circuit board, which hopefully will be replaced tomorrow and then actually fix the problem.

I await with a bit of confidence.....

[Danny 57]

Good luck and I hope it solves your problem.

[Morgan621]

Picked up the car todday and await with hope. The radio still cuts out after a few seconds everytime so I am not convinced that the problem has been solved, but willing to wait and see.