DoctorT

ah, no i hadn't, I think that post coincided with my door lock change and the problem going away. I just need to look into how i fool the car into thinking the bonnet is shut as i've got no idea where the sensor is for that, nor how it works, likewise i guess i need to fool the drivers door too so i can get at the fuses in there? although given pulling fuse 19 solves the issue i'm guessing thats the one, although what i wasnt sure of was whether something else, like a lock could be at fault, which keeps the car awake, but without the stereo fuse in, the car being awake doesn't matter because in the 'awake' state its the stereo being awake that is responsible for the noticeable excessive draw?

Okay so i've made a few other posts in the past in my attempts to get to the bottom of my battery drain issue. From pulling out fuses while measuring the amps being drawn from the battery I found that pulling fuse 19 which the manual says is for the radio stopped the drain. However, given the aftermarket stereo i have, had been in for 6 months or so before any sign of a battery drain issue reared its ugly head i was a little concerned about going down the route of blaming the stereo. i thought i had solved it previously when i found that the drivers side rear door wasn't actually locking everytime, and then eventually stopped working all together. I had the lock mechanism changed and all seemed well, then a few weeks ago i went to use the car and it wouldn't start. oddly once i tried to open the book when the car was locked just to check it was locked and it released, evenn though the doors were all locked, i just brushed it off but no i wonder if i'm seeing the start of a problem. I've been out with the car trying to see if anything repeatable is happening and found this, when i lock the car usually the amps drop to read 0.00-0.03 on a 10amp setting. If i lock the car usually i can watch the amps drop from 0.8 after pressing lock on the fob to 0.00-0.03 within a few minutes, however, if i then go and press the lock on the hatchback as if i'm going to open it (it shouldn't open as the car is locked, butyou can feel the push button depress), the amps jump up to 0.7A and stay there (with a periodic fluctuation down to 0.4A) once i've caused this rise in amps by pressing the release button even unlocking and locking the car doesn't help, but if i open and slam the hatchback it seems to solve it. Has anyone else experience this or had to change the release button on the boot? Cheers Gavin

I have just replaced the r1 and r2 relays in my Octavia (its a pre facelift 06 plate 2.0 tfsi VRS model) while trying to sort out an electrical issue (battery drain). In talking to the dealer I was told the r1 and r2 relays are the same, the r4 is something to do with the ABS or something (which i think might be the 458 one you mention) and r4 is something related to an automatic transmission, so it's empty on my manual car. I purchased my relays in June and July this year so this part code could still be the current one. The part that i was told was correct for my car, and my car seems to work fine with them in, was S4H0951253 (description next to part code is 'N/STK RELAY') and each one set me back 17.93 including the VAT. Just by way of a sense check, mine were light green in colour. As has been said above, you really need to use your chassis number to sort this out and ensure you get the correct part, but if your local dealer doesn't seem to be able to help, this infomation could be useful. (obviously you use this info at your own risk, i have no idea if this relay is the correct one for your car). Hope you sort it out.

just to close this off (hopefully), the new battery has solved my problems, i guess judging by the high draw i saw when i connected the multimeter suggests one of the relays I replaced was dying as well, although i couldn't seem to repeat this by swapping the bad ones back in after putting the new ones in, but then i have heard of sticky relays that fire when you put them in or pull them out but then fail to switch in normal use so maybe it's that. Eitherway, £35 on a couple of relays and warranty change on the battery and the car appears to be behaving itself.

So after charging the battery for a good 5 hours I took it to halfords yesterday and they tested the battery and agreed it needed replacing. Sadly my local store (less than 5 mins drive) didn't have the correct battery in stock. And no surprise the car wouldn't start again, so they called the next nearest store, told them they'd done the test and reserved a battery for me then jump started my car for me. The new battery appears to be okay, well things are looking good so far, yesterday evening the battery was showing a constant 12.65V and this morning at 9am it was still reading 12.45V. I'll check it a few ties during the day and see how things go.

well this morning at 10am it was down to just over 8V. I've spoken to my local halfords where i got the battery and they agreed it sounded like it needs replacing so i'll charge it up for a few hours then head over for them to test it. fingers crossed they replace it without issue and it solves my problems. It's such a pain having a car you can't rely on.

just been out again, at 11.30pm its down to 10.88V I put the multimeter between the -ve wire and the -ve terminal to complete the circuit and check the draw. Same deal as before, with ecar unlocked it drawing 0.8A but once locked, even with the bonnet up within a matter of 2 or so minutes, its down to reading 0.00 to 0.02 A which should be fine. Unless i'm missing something it looking like all of this has killed the battery. I guess the next step is to disconnect the battery from the car and see if it holds its charge then.

well at 10.30pm it's reading 11.26V I might have to disconnect the battery and check that it's not the battery that's dead, it's only 6 months old and it's a yuasa item but it has been put through the mill over the past couple of months as i try to narrow this issue down.

Ah okay, I had a VCDS scan done by Aston Bodger from this forum a few months ago when this battery drain issue began and it didn't show up any of those codes so i'm guessing i'm okay on that front. I took the car off charge just before 7pm and checked the voltage at 7pm which read 12.54V. I'll check it again later tonight and see if it's heading down by the hour like it was before, hopefully not given the drain is hugely less than when I measured it the first time. It was originally 0.7 - 0.9A and now its 0.01 - 0.02A.

hmmmm, i'm not sure about the can bus wire question. I made this video and at about 7.30 mins in you can see what i connected up. Does that tell us whether i did single or two wire mode? https://www.youtube.com/watch?v=vYKlCtghqk0

so after 20 minutes or so sat locked but with the bonnet open i've see a draw fluctuating mostly between 0.00 to 0.01 amps with the ocassional spike to 0.02 amps, i watched for just over a minute and saw less than a few seconds worth of 0.02 amps being displayed (i have my multimeter set to the 10A scale/setting) If any one has any experience of this i'd appreciate any imput. Cheers

okay so I managed to get another new relay and have put that in the car. I've connected up my multimeter by disconnecting the negative terminal and completing the circuit with the meter. The bonnet is still open and I haven't fooled the car into thinking its shut, which might stop it entering sleep mode. I see a spike of current up to around 8 amps when i unlock the car and holds at 0.84 amps if left sat unlocked, When I lock it, I see a spike to around 2.5 to 3 amps followed by a quick fall to 0.84 amps which over the next 3 minutes or so drops to 0.24 and finally onto a stable/steady fluctuation between 0.03 to 0.00. My understanding is that this means it's drawing 30mA which is less then the 40mA VW say is okay. Does that sound right or can I not tell with the bonnet open. I'll check it again in a minute and then again 15 mins later to see what it's reading.

okay so another twist, there are 2 relays in the fuse box under the bonnet that are the same part code and both seem to be responsible in some way for getting 12V power from the engine bay into the cabin as far as i understand. i replaced one of these with a new part and the problem continued, showing the same temporary fix, that if i removed the radio fuse, the battery drain stopped. Yesterday i swapped over the new relay with the other old one that i left in. This morning the car only just about started, and once 15 minutes down the road wouldn't restart at all even with the radio fuse still being out. Both yesterday and the day before the car had been used for good runs (around 25 miles each way each day) so the battery should be okay. Strange how swapping the relays has drained the battery overnight pretty much whereas without swapping them the car would last 3 weeks and still start without problem. I'm charging the car at the moment and have swapped the original relay that's still in there with the other original one I took out when i put the new one in. Hopefully i'll get something positive from it. Fingers crossed it's just a dead relay that'll cost just over a tenner or so.

oh and just to add, the battery was too low to start the car the following morning, so working central locking hasn't solved the battery drain!!

I'll drop the glovebox out and see what gateway i have in at the moment as a next step. It just seems odd to me that i've had the stereo installed since last summer, i had a flat battery some time in the winter before christmas, it was the first night the temperature dropped below freezing so i just assumed the battery was past it's best and the cold snap finished it off, i bought a new battery and all was well. Then the problem starts 4 months later. The problem started shortly after i installed a hardwire for a speed camera detector, the first thing i did was remove the hardwire connection (i double checked and the fuse position I used was 100% an ignition switched live) and the problem persisted, i can only assume the problem starting at that time was coincidence. The only other thing obvious I can think of is that, when I was installing the hardwire I put the car in my workshop where I also have a wifi router, typically I leave the wifi off on the stereo but if it was on at the time I wonder if the stereo did any sort of upgrade/update and something changed. i'm just a little lost with the issue given the symptoms.