Rear Passenger Door Lights Playing Up

[DenisS]

Hi guys,
New member to Audi-Sport. I've been getting valuable info here, but got stuck today retrofitting puddle lights.
Rear passenger door seems to have become a slave from front passenger door. Puddle, hazard and window switch lights will only work when front passenger door open? Videos for reference.




Had a look at wiring inside rubber grommet and all good there.
Can someone shed some light pls?? Maybe a coding problem?
Cheers
D

 

[George Kost]

In which pins did you connect the puddle lights?
front and back.

I would reverse the whole job and check if the problem is resolved at some point.
Instead of unpinning the connectors I think you can just unplug the plugs from the puddle and warning lights.

 

[DenisS]

In which pins did you connect the puddle lights?
front and back.

I would reverse the whole job and check if the problem is resolved at some point.
Instead of unpinning the connectors I think you can just unplug the plugs from the puddle and warning lights.

Hi George, do you mean the pins on to the main loom grey connector?

 

[George Kost]

Yes.
Did you go with 18 and 19 front and 1 and 2 rear?
Iirc those are the pins.
Try to unplug the lights and see if this solves the issue with the button illumination as well.

 

[DenisS]

Yes.
Did you go with 18 and 19 front and 1 and 2 rear?
Iirc those are the pins.
Try to unplug the lights and see if this solves the issue with the button illumination as well.

Yes, 18 and 19 front & 1 and 2 rear. Window switch position 1 onto 22, 2-4 and 3-8.
Tried unplugging lights and leaving just window switch plugged but no joy.
Say doors have opening positions 1 & 2 been 2 wider. Seems like when opening as soon as front passenger door goes past position 1 everything works, then past position 1 into closing everything stops working. Mind you, speakers and window switch work normally.

 

[George Kost]

Check again the cables on the door hinges. From the 20pin connector of the module, to the connector at the door.
Both front and rear door.

For example pin 15 at the 20pin connector (T20g/15) of the front door module goes through the hinge loom to the rear door at pin 8 of the 20pin connector (T20n/8) of the rear door module.

I hope the diagrams will help you.

 

[DenisS]

Check again the cables on the door hinges. From the 20pin connector of the module, to the connector at the door.
Both front and rear door.

For example pin 15 at the 20pin connector (T20g/15) of the front door module goes through the hinge loom to the rear door at pin 8 of the 20pin connector (T20n/8) of the rear door module.

I hope the diagrams will help you.

Thanks for the diagram George. Went back to check door hinges again and turns out the live cable on the front door was cracked so close to contact terminal that i missed at first glance. Didn't know those cables would interfere with the rear door functions but hey ho....

I had already replaced the harness on the drivers side as they were all cracked. Suppose its time to do the same on driver's side. I've used this and it seems a good choice as these seem more flexible than original ones.

https://www.ebay.co.uk/itm/Repair-Kit-Audi-A3-8P-Door-Pillar-Wiring-Harness-Loom/174452287640

 

[George Kost]

Happy you found it mate!
I first saw this problem at a friends A3 with similar problems and it was broken cables at the front door hinge.

 

[NHN]

Front doors at a certain year point relayed bus signals from the rears, hence why if power down at front rears goto shxt, it used to be bus wired individually, but some bright spark at Audi decided, oh lets cut back on urmmm few metres of wires & control rear doors via fronts, great move.......