Electrical Funnies - Drivers door wiring?

[kooky_guy]

Hi All,

My 52 A4 has started a series of electrical problems which I'm hoping are all related...

Firstly the remote part of the central locking suddenly packed up. It had misbehaved intermittently a few weeks before but seemed to sort itself out. Now, suddenly it is completely dead. The physical key will only unlock the drivers door (until the ignition has been turned on, at which point the physical key will then unlock the other doors if I take it out again and stick it in the door lock (this may be normal - I have no manual so can't tell). The door lock/unlock button on the inside of the door does not unlock the other doors. Should it?

Now, suddenly the drivers door electric window has stopped working (luckily it's stuck closed). even turning the key in the door won't move it - the easy open/close function (or whatever it's called) works on all of the others).

Thirdly (and I can't really see how this is related, but it started happening in the same time frame (ie the last week), the radio reception has suddenly become intermittently very poor - as though the aerial lead has a loose connection...

Now I'm guessing that these are probably all related to the convenience module (or whatever it's called). I've had a quick look at the carpet and it seems to be bone dry. Is there anything else to physically check around the module, or do I need to disconnect it and check the connector pins? Is there a guide anywhere on how to do this (ie remove the carpet etc)? I've not come across one.

The other possible cause that I've come across on my googling is that the drivers door wiring harness is prone to fatigue and that a couple of broken wires in it can cause these issues (although, I can't see how the radio would fit in). Is there a common point at which these wires break and if so is it the same wires each time, or should I think about replacing the entire door harness? Easy job?

Any thoughts and/or sugggestions would be welcomed.

[richie190784]

Have you checked under the ecu to check if the drain holes are blocked if it is then water will enter the car thru these wires into the convenience module?

The ECU is the box on the off side at the top of the bonnet under the plenum cover if there is one.

[kooky_guy]

Have you checked under the ecu to check if the drain holes are blocked if it is then water will enter the car thru these wires into the convenience module?

The ECU is the box on the off side at the top of the bonnet under the plenum cover if there is one.

Hi,

I did try and have a quick look, but couldn't work out where the drain holes are supposed to be. Do I need to take the battery out to find them?

The carpet shows no sign of ever having been wet though.

[fourringsrus]

Kooky, not sure about the reception queery, but I would suggest the loom in the drivers door is as you have read, I have repaired my 52 A4 cabby drivers door loom 3 times for exactly the same faults and a couple of others. Its not particularly easy to work on in the hinge area but it is workable with a bit of patience.

Stuart

[kooky_guy]

Kooky, not sure about the reception queery, but I would suggest the loom in the drivers door is as you have read, I have repaired my 52 A4 cabby drivers door loom 3 times for exactly the same faults and a couple of others. Its not particularly easy to work on in the hinge area but it is workable with a bit of patience.

Stuart

Hi Stuart,

How did you find the breaks - were they physically obvious, or did you have to test each wire? Were they all in the flexi part? I have a wiring diagram in the Haynes book so could do this, I suppose.

I assume there is a multiplug at the door pillar end of the loom? Can this be disconnected without removing trim? I'm half tempted to just buy a new loom regardless but have no idea where to get Audi parts yet - not had this car very long.

[fourringsrus]

Hi buddy, yes easy to see the breaks once the flexi boot is peeled open.
There are quite a few wires inside, of varying thickness, which are a bit fiddly to access because of the lack of space in that area.
There is a multiplug arrangement which again is fiddly to remove, the "tongues" that make the click fit of the plug are difficult to squeeze in to release but it is do-able.
Ref loom replacement, I think the multiplug detaches from the car side but not from the door side,not sure, but maybe a loom comprises everything in the door.
The door card would only need removing if the loom inside is to be replaced, but no trim removal needed if just attempting a repair in the door slam area.
Good luck and as a p.s remember my info is based on experience with the two door cabriolet A4(2002 52 PLATE) but I would imagine the job on a four door to be pretty much the same.

Stuart

[imc042]

Hi guys,

I really don't mean to hijack this thread or anything but my issue is very similar to this. Firstly, my remote central locking went on the blink. Worked one day, didn't work the next. Thinking it was the battery inside the key I bought one at the filling station and replaced it. Seemed to work better for a while and then became intermittent again.

Then, the electric windows started going on the blink (not just driver side, both front windows together, my back windows are manual). Then the right dipped headlight, working sometimes, sometimes not. And most recently the interior light that comes on when you unlock the car is staying on after you start the car and you have to set it to OFF to get it off.

All of these problems are intermittent but are after getting progressively worse. I had my NCT test this morning, hoping it would be okay but it failed because of the windows and the right dipped headlight (both of which were working on the way to the test centre!). I have also replaced the car's own battery for 135 euro just two weeks ago and that did not help at all.

Rang the Audi garage in Cork and the woman said that it costs 68 euro an hour to take the car in there. I would really like to try and fix this myself if I could. Also, since I bought the car 2 years ago, I have always had poor radio reception. Works good in the city centre but where I live 25 miles from the city I can't pick up any stations.

Hopefully, me and kooky_guy have the same issue here and we can fix it ourselves?

Edit: By the way, mine is a 2002 Audi A4 Diesel Saloon 130bhp (The B6 one)

[fourringsrus]

Hi guys,

I really don't mean to hijack this thread or anything but my issue is very similar to this. Firstly, my remote central locking went on the blink. Worked one day, didn't work the next. Thinking it was the battery inside the key I bought one at the filling station and replaced it. Seemed to work better for a while and then became intermittent again.

Then, the electric windows started going on the blink (not just driver side, both front windows together, my back windows are manual). Then the right dipped headlight, working sometimes, sometimes not. And most recently the interior light that comes on when you unlock the car is staying on after you start the car and you have to set it to OFF to get it off.

All of these problems are intermittent but are after getting progressively worse. I had my NCT test this morning, hoping it would be okay but it failed because of the windows and the right dipped headlight (both of which were working on the way to the test centre!). I have also replaced the car's own battery for 135 euro just two weeks ago and that did not help at all.

Rang the Audi garage in Cork and the woman said that it costs 68 euro an hour to take the car in there. I would really like to try and fix this myself if I could. Also, since I bought the car 2 years ago, I have always had poor radio reception. Works good in the city centre but where I live 25 miles from the city I can't pick up any stations.

Hopefully, me and kooky_guy have the same issue here and we can fix it ourselves?

Edit: By the way, mine is a 2002 Audi A4 Diesel Saloon 130bhp (The B6 one)


Hi matey, with all the electric gremlins you are having, I would firstly take a close look at the cars' earth points ensuring good , clean and strong connections; ie battery earth to body lead etc.
Your windows issue could although be a car earth problem, also be down to the same issues relating to the door loom like Kookies possibly.
You may even have an issue with the cars' comfort module, something I know nothing about unfortunately, but someone on the forum will be able to advise.
In relation to the radio reception, this is most likely down to a failing or failed aerial booster/amplifier which is located somewhere inside the roof lining above the rear screen. I had exactly the same issue om my previous 2002 A4 3.0 quattro but sold the car before sorting it out.
Headlight bulb, possibly again down to poor earth connection or simply a dud bulb holder/wiring to the lamp unit.
Do a forum search to find a member near you who has or has access to vagcom/vcds.
I would be confident in suggesting that all of the issues on both the cars above will be traceable via a vcds/vagcom fault code reading.
Good luck boys

Stuart

[dan2134]

It sounds like the door loom has broken wires in it. to be honest the best repair is replace the door loom they cost about £100 from audi and take about an hour to fit. when mine went it been repaired once or twice before and was not worth repairing again. hope this helps.



A4 1.9tdi sport avant 2002

[imc042]

Thanks guys.

Okay, so I found another post where the poster also had the interior dome light staying on and no electric window function plus remote central locking opening all doors except driver door (exactly like me). Now I am certain that there must be damaged wires in the wiring loom in the driver door OR the Door Control Module is having a fault.

As for the right dipped headlight and the radio reception, I'm not sure. I don't care about the radio really, and the light may simply be a bulb.

He replaced the wiring loom with a new one and it still was not working. A VAG Com scan then told him this:

01331 - Door Control Module; Driver Side (J386)
49-10 - No Communications - Intermittent

The part no for the wiring harness is "8E1 971 029 C" and for the Comfort/Door Control Module is "8E0 907 279 E". I work in a phone repair center so I might be able to remove the wiring loom, solder any damaged wires and test before I go spending money on parts. Will keep posting on this thread as I work on this.

[kooky_guy]

It sounds like the door loom has broken wires in it. to be honest the best repair is replace the door loom they cost about £100 from audi and take about an hour to fit. when mine went it been repaired once or twice before and was not worth repairing again. hope this helps.



A4 1.9tdi sport avant 2002

Just had the door trim off - it's clearly been off before going by the number of broken clips!

There appear to be two distinct looms. On mine, they are numbered 8E1 971 035AF (trim part) and 8E1 971 029B for what appears to be the part that goes through the flexi. Does the £100 include both of these looms? It seems a little excessive even if so!

The ones I've seen on ebay all seem to be one piece though. I'm confused now.

I can't work out how to disconnect the flexi to examine the wires inside it. Having a sulk now! :aargh4:

[kooky_guy]

Just found this walkthrough which is slightly helpful:

http://forums.audiworld.com/showthread.php?t=2379267

[kooky_guy]

Well that's something I don't relish having to do again.

Removed the flexi covering and found the orange / brown wire broken. Think this is the CAN BUS LO connection according to my Haynes book of lies. It had been repaired previously and broken again. Looks like a number of other wires are about to go too. I've taped them up, but I think I'm going to need a new loom. It was a right bugger trying to solder in a new section for the broken wire.

I can't work out how to get the rubber boot back onto the door now. Is there a trick to it? The A pillar end is easy.

Anyway, it's fixed my drivers door window, the central locking weirdness, but not the remote central locking problem - although I'm hoping this may just be a sync issue - not entirely sure about the correct procedure, but nothing I've tried works yet. I know the fob itself is working as it was tested.

Another seemingly unrelated problem that it also fixed was the door switch on the rear drivers side door. I assumed this was a completely different problem so it just goes to show that weird things can happen when this wire is broken.

Not sure about the radio problem although I really can't see how that could possibly be related - it's currently working, but it was before I started the job so hard to say.

Anyway, thanks for all the info all. Where is the best place to get Audi parts such as this loom?

Guy

[richie190784]

Try your local TPS place.... Trade Parts Specialists (http://www.thetradepartsspecialists.co.uk/)

[fourringsrus]

Well that's something I don't relish having to do again.

Removed the flexi covering and found the orange / brown wire broken. Think this is the CAN BUS LO connection according to my Haynes book of lies. It had been repaired previously and broken again. Looks like a number of other wires are about to go too. I've taped them up, but I think I'm going to need a new loom. It was a right bugger trying to solder in a new section for the broken wire.

I can't work out how to get the rubber boot back onto the door now. Is there a trick to it? The A pillar end is easy.

Anyway, it's fixed my drivers door window, the central locking weirdness, but not the remote central locking problem - although I'm hoping this may just be a sync issue - not entirely sure about the correct procedure, but nothing I've tried works yet. I know the fob itself is working as it was tested.

Another seemingly unrelated problem that it also fixed was the door switch on the rear drivers side door. I assumed this was a completely different problem so it just goes to show that weird things can happen when this wire is broken.

Not sure about the radio problem although I really can't see how that could possibly be related - it's currently working, but it was before I started the job so hard to say.

Anyway, thanks for all the info all. Where is the best place to get Audi parts such as this loom?

Guy


Ref the rubber boot, I found that with the door speaker removed, I could access the internal side of the plastic plug assembly.
With this plug, when looking inside the door towards the aperture, you can squeeze the lock tabs and push the unit into the open area between the car and door, this then makes it much simpler to re- seat the end of the rubber gromit into its' locating groove around the plastic plug.

Ref the other central locking queery, are you sure , 100%, that no other wires are damaged, as this was exactly why I had to repair just last weekend, the door would not lock/unlock on the flip key blipper.

The radio, I'm sure is totally unrelated and I would say again that the aerial amplifier in the rear roof above the rear screen, is dud or on its' way out, from memory I think I was quoted around £50-60 for a genuine Audi part around 5-6 years ago, plus fitting.

As said by other poster, your part is best bought from TPS ( genuine parts supplied) or direct from Audi themselves.

Stuart

[imc042]

Well that's something I don't relish having to do again.

Removed the flexi covering and found the orange / brown wire broken. Think this is the CAN BUS LO connection according to my Haynes book of lies. It had been repaired previously and broken again. Looks like a number of other wires are about to go too. I've taped them up, but I think I'm going to need a new loom. It was a right bugger trying to solder in a new section for the broken wire.

I can't work out how to get the rubber boot back onto the door now. Is there a trick to it? The A pillar end is easy.

Anyway, it's fixed my drivers door window, the central locking weirdness, but not the remote central locking problem - although I'm hoping this may just be a sync issue - not entirely sure about the correct procedure, but nothing I've tried works yet. I know the fob itself is working as it was tested.

Another seemingly unrelated problem that it also fixed was the door switch on the rear drivers side door. I assumed this was a completely different problem so it just goes to show that weird things can happen when this wire is broken.

Not sure about the radio problem although I really can't see how that could possibly be related - it's currently working, but it was before I started the job so hard to say.

Anyway, thanks for all the info all. Where is the best place to get Audi parts such as this loom?

Guy

Me too. :D Removed the flexi covering and found the thickest brown wire completely split apart. Also the other thick wire, red with black stripe, is halfway broken. Touching both ends of the brown wire together brings back both electric windows, fixes interior light staying on, electric mirrors working again, switch on door for central locking working again, red lights on doors working, central locking and automatic windows going up and down with the key working again.

My brother thinks that I'm completely mad to buy a new loom, he said I should just get 2 of those insulated wire terminals and rejoin the brown and red/black wires together. I supposed I really would be wasting money if I spent 100 euro on a new loom??

I still have a problem with my right dipped headlight, and was wondering how you guys would recommend getting access to it to check the bulb? Should I take the whole light out or should I try and get at it from behind. The trouble is that there is a big thing in the way that will need to be removed before I can access the bulb from behind.

I'd also still like to investigate the radio reception issue too. Let me know if you come up with anything kooky! ;)

[ajrayner]

Repair terminals used in auto electrics are poor quality and bulky and would likely damage the other wires in such a compact and stressed area. Ideally, solder the wires together, or solder a link wire in, then use some self-amalgamating tape (http://www.ebay.co.uk/sch/i.html?_trksid=p3984.m570.l1311.R1.TR4.TRC0&_nkw=self+amalgamating+tape&_sacat=0&_from=R40) to insulate. Wrapping the whole loom with this stuff would help protect it, too.

For key re-sync, google it...it's all over the web.

To check/change headlight bulbs you have to remove the headlights. Remove x2 torx screws on lock carrier and loosen x2 lower torx screws (per headlight) then pull out and disconnect. Driver's side requires you to remove the intake air guide - x2 cross-point screws on lock carrier.

As already said, radio issue will most certainly be the aerial power amp located in the roof trim

[fourringsrus]

Repair terminals used in auto electrics are poor quality and bulky and would likely damage the other wires in such a compact and stressed area. Ideally, solder the wires together, or solder a link wire in, then use some self-amalgamating tape (http://www.ebay.co.uk/sch/i.html?_trksid=p3984.m570.l1311.R1.TR4.TRC0&_nkw=self+amalgamating+tape&_sacat=0&_from=R40) to insulate. Wrapping the whole loom with this stuff would help protect it, too.

For key re-sync, google it...it's all over the web.

To check/change headlight bulbs you have to remove the headlights. Remove x2 torx screws on lock carrier and loosen x2 lower torx screws (per headlight) then pull out and disconnect. Driver's side requires you to remove the intake air guide - x2 cross-point screws on lock carrier.

As already said, radio issue will most certainly be the aerial power amp located in the roof trim


Ditto to every point made here. EXACTLY
The point made ref the terminal connectors is indeed valid, been there three times now, the bulkiness actually just puts more inside the rubber boot potentially crushing the other fragile wires, I will replace my loom the next time but each time this has happened it has not been at a convenient time to purchase new loom.

[kooky_guy]

Thanks all for the great advice. It's entirely possible there is another broken wire - I just taped the other obviously damaged ones up to try and reinforce the insulation, but they could be broken. Think I'll look out for a replacement loom - it sounds like the best option, given how badly my soldering went! I'm sure that I used to be able to solder...

Anyway, thanks again.
Guy

[ajrayner]

Low heat and lots of flux on small gauge wires but if you have several "tired" wires then perhaps a new loom is the way forward. Either that or solder splice wire of the same gauge by cutting out the door hinge section and solder splice in the door at one end, and cabin at the other. Tricky but a few quid for some replacement wire versus £100 for a loom.