Electrical problem - advice needed (real long post)

[Matt_D]

Hi all,

I need some advice as to what this problem on my S2 could be, if anyone could help me on this i would be very very grateful

I bought my car from Idub on here and i knew it has this problem when i bought it but before i start replacing things i wonder if anyone on here could shed some light.

Basically this happens sometimes -> when the ignition is turned off after a drive or just flicking the ignition on and off the autocheck, dash lights, diff lock switch and all the fog lights, hazard switches are all still lit up and the ABS unit clicks as if the ignition is on still.
This lasts anything up to a minute wether the keys are in the ignition or not.
The lights are dimmer than usual and can flicker as though there is a low voltage leak somewhere, but other times there is enough voltage to switch on the ECU (can hear a click) and sets the alarm off as it thinks its being hotwired.
During this time when trying to switch on the wipers, heater, rear window heater or trying the windows nothing works.

Idub did post about this before here:

http://www.s2forum.com/forum/showthread.php?t=19539

And JohnF also posted about this, he was the previous owner before Idub: (bottom of page)

http://www.s2forum.com/forum/showthread.php?p=195083

I did have the battery off for 12 hours last week as i was cleaning up the earth lead in the boot to ensure a proper connection as i was told it could be a bad earth.
It seemed to have sorted this as it did'nt go off from Friday afternoon when the battery went back on til Monday sometime.
I have since added an earth lead from the engine block to the strut brace and another earth lead from the battery to another earthing point in the boot by the rear lights, But its still happening

...And just to add to the confusion

Whichever previous owner changed the battery they did'nt add the breather pipe to the battery, i did read on here that this could damage the alternator is this true and could it be the cause of my problem ??
Although my gauge does say that its charging at 14v at idle and i have no problems with a flat battery.

I have had the wiring repaired in the tailgate hinge area professionally that Idub mentioned in the link above so its not that, and there is no damp in the fusebox either.

I did think it could be an ignition switch but when the dash lights came on i unplugged the ignition switch and they remained, surely if it was an igntion switch shorting out the lights would go out immediatley ??

I also had the ECU unplugged and it happened so its not that either, thankfully!

Could it be the voltage regulator shorting out or possibly a damaged battery?

As i said any help would be very much appreciated
Cheers

[Fat Audi 80]

I have only speed read that, and didnt read the referring post but have you tried a new ignition switch to start with?

[john881000]

warning lights/malfunction

hi there

just speed read your posting
one thought is as you quickly mentioned is alternator

i realise that its not easiest thing to disconnect in place but if posible ...as problem persists try to disconnect it first one cable at a time/both and protect


we experianced problems with them on early A4

i realise you cant compair the two cars but in our w/shop an faulty internals in alternator gave big headaches


just my two xcents

cheers
john

[Matt_D]

I have only speed read that, and didnt read the referring post but have you tried a new ignition switch to start with?

No i have not as yet, i was thinking of changing this but i thought i'd ask some advice first. Don't really want to change this if somebody thinks its nothing to do with this or has an idea of what it might be.

hi there

just speed read your posting
one thought is as you quickly mentioned is alternator

i realise that its not easiest thing to disconnect in place but if posible ...as problem persists try to disconnect it first one cable at a time/both and protect


we experianced problems with them on early A4

i realise you cant compair the two cars but in our w/shop an faulty internals in alternator gave big headaches


just my two xcents

cheers
john

Cheers John.
I will try and disconnect it and see, one reason why i think it maybe the alternator is that the battery symbol sometimes pops up on the autocheck display when the dash lights are on.

Keep em coming chaps

[panzerwagen]

Matt you are thinking about this too much! Think basic...

and simple. Go back and look at your posting. You are seeking the answer to a question that you have already answered in a way. Look where the evidence of the problem is. It is behind the dash or in the area of the firewall. But first check the alternator and starter for ground problems. May I suggest you get a hold of the wiring schematics and a multimeter? Believe me when you see the schematics you will understand what I am explaining.

[Jamo]

I'd have thought the place to start is the ignition and then also investigate if the car had a aftermarket alarm fitted / removed?

[Matt_D]

and simple. Go back and look at your posting. You are seeking the answer to a question that you have already answered in a way. Look where the evidence of the problem is. It is behind the dash or in the area of the firewall. But first check the alternator and starter for ground problems. May I suggest you get a hold of the wiring schematics and a multimeter? Believe me when you see the schematics you will understand what I am explaining.

I know i'm confused by it all as so many things happens, so when you say the problem is behind the dash by that you mean the ignition switch ?

I'd have thought the place to start is the ignition and then also investigate if the car had a aftermarket alarm fitted / removed?

The car has a Cobra CAT1 fitted but its one i had fitted 3 weeks ago, it did this before that.
I thought it might be the ignition switch but then again when the dash lights were on i unplugged the ignition switch and they still stayed on
Don't really want to take half my dash apart to get the dash clocks out and replace the ignition switch if it does'nt solve the problem thats all.

[panzerwagen]

MattD here is what I would suggest...

Get the schematics that I have mentioned. Check the wiring before you start hacking around back there.
It will save you alot of heartache and sleepless nites. It is either a short in the wiring or you
have a ground problem that is activating the problem

[terrybullwon]

I have a new ignition switch if you wish to try one

I had a right pita with mine, you could also turn it to the off position and remove the key and the dash would stay lit up

[Matt_D]

I have a new ignition switch if you wish to try one

I had a right pita with mine, you could also turn it to the off position and remove the key and the dash would stay lit up

I'll bear that in mind mate many thanks for the offer

[Alistair E]

Got home last night, went into the house and a minute later the alarm was going. The car had a spell of doing this last year but I never got round to trying to find the source of the problem. I guessed it was a fault with the alarm.
It started doing it again a few weeks ago. Then I noticed I had a water leak into the passenger footwell. I've just started to try to find the source of the leak which appears to come from somewhere around the base of the windscreen pillar towards the door side. I thought the two problems may be related in some way.
Anyway, when I went out to the car last night, I sat in it for a minute and was going to check if the passenger footwell carpet was wet. It was then that I noticed some of the warning lamps on the dash were glowing slightly. Initially it was just the handbrake light. Then I saw the ABS light glow a bit. I turned the inignition on and off, took the keys out and the lights stayed on but a bit brighter. I also had the autocheck OK light come on for 5 secs.
Having read this thread I now believe that this is probably the reason for the dodgy alarm. The other problem is, the lights were so dim initially that I don't think they would be visible in daylight.
Has anyone got any further information on this fault. The carpet was dry on the surface but I'm not sure about underneath. Is there anything under the carpet on the passenger side which may be causing this? Should I really be looking at the ignition side of things for a fault there? Any help gratefully received as I've just had to go out to the car park, in the rain, to switch the alarm off again.

Thanks

Alistair

[ericd]

years ago for electrical gremlins we used to disconnect both +ve and -ve leads from the power source and connect/touch them together for a wee spell , I'm skipping the lesson on why this works (my lecturing days are past), but lets just say it gets rid of any bad static in the system.

I'm not saying it gonna fix/eradicate some of the problems mentioned in this thread, but for a few seconds work (few minutes, I guess removing the rear seat), this is worth a try.


BTW

I know they're still using this particular technique on at least one major maufacturers vehicles to solve other electrical gremlins/glitches

[Matt_D]

Got home last night, went into the house and a minute later the alarm was going. The car had a spell of doing this last year but I never got round to trying to find the source of the problem. I guessed it was a fault with the alarm.
It started doing it again a few weeks ago. Then I noticed I had a water leak into the passenger footwell. I've just started to try to find the source of the leak which appears to come from somewhere around the base of the windscreen pillar towards the door side. I thought the two problems may be related in some way.
Anyway, when I went out to the car last night, I sat in it for a minute and was going to check if the passenger footwell carpet was wet. It was then that I noticed some of the warning lamps on the dash were glowing slightly. Initially it was just the handbrake light. Then I saw the ABS light glow a bit. I turned the inignition on and off, took the keys out and the lights stayed on but a bit brighter. I also had the autocheck OK light come on for 5 secs.
Having read this thread I now believe that this is probably the reason for the dodgy alarm. The other problem is, the lights were so dim initially that I don't think they would be visible in daylight.
Has anyone got any further information on this fault. The carpet was dry on the surface but I'm not sure about underneath. Is there anything under the carpet on the passenger side which may be causing this? Should I really be looking at the ignition side of things for a fault there? Any help gratefully received as I've just had to go out to the car park, in the rain, to switch the alarm off again.

Thanks

Alistair

Alistair,
The dash lights popping up will almost certainly set off the alarm.
Mine has not down this in ages now (5 months) what i have done to cure this i'm not sure but what i have replaced/done is:

1. Had a alarm fitted by a approved centre, i asked them to disable the standard alarm which they have not done as i can lock it with the key and the alarm will come on, but they did take out a lot of wiring they said was to do with the standard alarm ?!?
2. I took out all the fuses and relays out of the fusebox under the bonnet to see if i could see any moisture or rust on any of the connectors. There was not any thankfully but make sure the seal around the fusebox lid is properly secured in the groove in which its supposed to sit and make sure the lid goes back on properly. I also chucked in a couple of samll bags of silica gel (the kind you get with new shoes) to 'soak up' any moisture i did'nt spot
3. Replaced the ignition a switch as i thought this was playing up, needed doing as the key was hard to turn at times
4. Checked the connectors on the back of the alternator, take them off and give them a good rub with some sandpaper to clean up the connectors and ensure a good contact is had
5. Added two more earth straps as the one from the -ve terminal of the battery in the boot of the avant is frankly pathetic, i added one from the -ve connector to a bolt that i think is used to hold the indicator lense further on up from the standard earthing area and one from the engine block to one of the bolts on the strut brace
6. Had the wiring replaced in the back of the car where the loom comes from the roof area and into the tailgate, this over time has split where the boot has opened and closed hundreds of times

As for wiring under the carpet passenger side i'm not sure but i do know the ecu is under the glovebox, perhaps a windscreen seal has gone and the ecu is getting moisture ?
I hope the wet carpet you have is not from a leaking heater matrix/water pipe as this i've heard is a absolute git to change.

On the avant (i'm not sure on the the coupe) the pollen filter is under the windscreen cowling on the passenger side perhaps this is filling with water as a seal has gone ?!?

Hope this helps somehow although it probably does'nt.
I know how fustrating this can be especially when you have to jump out of bed at 3am due to your alarm going off.

Good luck!

[Alistair E]

Matt

Quite good timing on your reply as I was having a bit of a look last night when I got in. Not the best time to be checking wiring at 11pm with a torch, but I had got back and the handbrake and abs lights were glowing slightly.
I've got the drivers dash shelf and the glovebox out at the moment so I have access to the under dash wiring. I wasn't actually meter testing, just having a play with the wiring to see if anything was loose. Disconnected the switch from the back of the ignition key, no change and the lights continued to glow. I was pulling the looms around a bit and when I started shifting the wiring behind the centre console, the dash lights light up brightly for a second but then went back to their dim glow. The trouble is, I couldn't recreate this. I gave up at 11.30 without any further success.
As regards to some of your suggestions:
Pretty sure the leak is coming down the windscreen pillar. Poured water down the sunroof drain which came out by the door hinge as I believe it is supposed to. Don't believe it is the heater matrix due to the source of the leak being up towards the pillar. I'm looking to maybe remove some trim from the pillar to investigate. It looks like it might be the door seal as someone else has suggested but it isn't obvious so I'm not sure about that one.
Fuse box and pollen filter are bone dry.
I will continue at some point to check out the wiring, but it appears to be a bit of a mess in some areas. I think the wiring for the radio and what I believe to be the alarm look a bit suspect. Trouble is, I don't think I would be able to see the dash lights during the day.
I've had to stop setting the alarm, which obviously is a concern.
Thanks for the suggestions, I'll keep looking.
A question to anyone, A6 AVANT said that the door hinge can be adjusted to realign the doors. I had a quick look at the hinges, but it wasn't immediately obvious which bolts to loosen. Does anyone have any further information on this?

Thanks

Alistair

[Alistair E]

Still struggling with the glowing dash lights. Pulled the instrument cluster forward to check the wiring at the back. I'l have to have another go to check the colour coding on the wires, but I found I had positive supply to about 3/4 of the wires of the multipin plug on the right hand side of the cluster. Kept checking and after a while, the supply disappeared. Don't know why.
The other thing is, I was messing with the connector at the ecu and found that the ecu casing was hot. I had been on a 20mile drive. Is this normal? I wondered if the electrical fault could be somehow be related to the car temperature or ecu temperature. I also now have the battery warning signal appearing after a while and the autocheck beeps every so often.
Another fault, which has been there since I bought the car 6 years ago, is every so often the clock resets itself as if it has lost positive supply at some point. Never bothered about it before as it didn't seem like a big deal.
Anybody out there able to help shed some light on this? All suggestions gratefully received.

Alistair