Faulty Rear Interior Light Repair

[audifan]

Here is a picture to help...

 

[Aktiv8]

Door open sensor is inside the lock and not easy to get at. If the door open switch is not working there will be no DIS warning for that door being open.
You MAY be able to get the switch working by cleaning, but if the switch has failed or the cam that operates it has an issue then the microswitch and or lock assembly will need to be replaced and that involves removing all the door trim, the aluminium plate the winder motor, disconnecting the outer handle unpluging the loom then removing the entire upper half of the door that contains the glass.
To TRY to clean it spray WD40 into the rearmost gap of the black lock assembly just behind the part that rotates to lock the door to the hoop on the chassis. The open microswitch is directly below this. Spray the WD40 for about 5 seconds then using a screwdriver close the door lock open it using the handle and repeat this locking and opening a few times, then repeat the WD40 flush followed by the locking opening cycle another say 6 times. If it is covered in dirt and grease the cleaning may work. Clean up the mess created and check for DIS and interior lights.

@audifan thanks for this - much appreciated, will give it a try…. We were so chuffed to get the rear light working after finding this thread ?

 

[audifan]

As said if the problem is only dirt and grease then the cleaning should work if it is the microswitch or the coating on the cam broken up then a replacement lock assembly will be required. Once the old one is out it is quicker to just fit the replacement. Job looks daunting but it it not that hard and only a few tools required, but as the upper half of the door needs to be removed make sure the car is undercover and until the door rebuilt secure. If you discover you need or want to replace the rear lock give me a shout for more instructions.
Be warned that if the car does not know that the rear right door is open there is a high chance that you may lock the keys inside the car if you unlock it and only open the rear door to get something on the back seat and place the keys on the seat while doing so. The car will automatically relock and when you close the rear door your keys are trapped, so make sure that you have a second key available that will open the car either on the remote or the drivers door lock using the key blade.

 

[Aktiv8]

As said if the problem is only dirt and grease then the cleaning should work if it is the microswitch or the coating on the cam broken up then a replacement lock assembly will be required. Once the old one is out it is quicker to just fit the replacement. Job looks daunting but it it not that hard and only a few tools required, but as the upper half of the door needs to be removed make sure the car is undercover and until the door rebuilt secure. If you discover you need or want to replace the rear lock give me a shout for more instructions.
Be warned that if the car does not know that the rear right door is open there is a high chance that you may lock the keys inside the car if you unlock it and only open the rear door to get something on the back seat and place the keys on the seat while doing so. The car will automatically relock and when you close the rear door your keys are trapped, so make sure that you have a second key available that will open the car either on the remote or the drivers door lock using the key blade.

Thanks again - much appreciated ???

 

[ProjectGT]

Hello.

I noticed recently that when opening any of the doors, only the front interior lights illuminated. The rear lights would illuminate only when the front light was set to be always on using the rocker switch, which is different to other cars and certainly does not seem conventional. I began attempting a repair by checking the wiring to the front light, but all seemed well. I then removed the rear light by gently prising it out, it is held in by 4 spring clips and simply pulls out from the headlining. Again, the wiring to the light seemed fine, leading me to the possibility of the rear light unit itself being faulty.

I examined the joints on the PCB on the back of the unit with a magnifying glass to see a small ring around a soldered joint, which seemed to be a dry joint. I have circled the offending joint on the following photo.

View attachment 17183

To fix this, I heated the joint with a soldering iron and added a little solder. I then put the light back in the car, and it worked exactly as it should. When a door is opened, both the front and rear interior lights now illuminate. I checked our other A2 as well, just out of curiosity, and I found that this rear light was faulty in the same way, and that the exact same solder joint had failed! Both cars had the same problem. I also repaired this, which also now too works perfectly.

I'm not sure if this joint is a known weakness as a forum search revealed nothing, but it's a simple fix if you have a spare 5 minutes!

Regards,

Matt.

Thanks Matt, great advice and fixed within minutes as described.

Very pleasing indeed.

 

[mtl]

Hello.

I noticed recently that when opening any of the doors, only the front interior lights illuminated. The rear lights would illuminate only when the front light was set to be always on using the rocker switch, which is different to other cars and certainly does not seem conventional. I began attempting a repair by checking the wiring to the front light, but all seemed well. I then removed the rear light by gently prising it out, it is held in by 4 spring clips and simply pulls out from the headlining. Again, the wiring to the light seemed fine, leading me to the possibility of the rear light unit itself being faulty.

I examined the joints on the PCB on the back of the unit with a magnifying glass to see a small ring around a soldered joint, which seemed to be a dry joint. I have circled the offending joint on the following photo.

View attachment 17183

To fix this, I heated the joint with a soldering iron and added a little solder. I then put the light back in the car, and it worked exactly as it should. When a door is opened, both the front and rear interior lights now illuminate. I checked our other A2 as well, just out of curiosity, and I found that this rear light was faulty in the same way, and that the exact same solder joint had failed! Both cars had the same problem. I also repaired this, which also now too works perfectly.

I'm not sure if this joint is a known weakness as a forum search revealed nothing, but it's a simple fix if you have a spare 5 minutes!

Regards,

Matt.

Thank you for this, I had exactly the same dry joint problem on my rear interior light unit. And also on the reserve unit from breakers car. Now both work as they should.

 

[birtyA2]

Amazing, I think I may have this problem too, never noticed before. One to check at the weekend

J

 

[mtl]

I have also not noticed this, until now, when the days are shorter. Very easy repair and basically free .

 

[NeilA2]

Thanks to this thread I have just fixed my rear interiour light...hooray! It was a dry joint on exactly the pin in the original post. I did notice before resoldering that with the light pulled out, still connected and with power on (front interior light on) if you prod the offending joint it would make the rear light come on - proof that it was that pin.
Fixing this was a side project whilst I am trying to fix what I think is a faulty door micro switch. The symptom is every time you turn the ignition key to live you hear the door locks clunk. It sounds the same as when you unlock the car with the fob - a sort of double clunk. No big deal but it is getting really annoying. I have the rear drivers side passenger door skins off but am waiting for some XZN spline bits to arrive to get the main bolts out to release the lock assembly.
Anyway, the reason I'm adding this to the thread is that I was not sure which door switch may be causing the clunk so I started with that door by chance.
In fixing the light I noticed that the door I'm working on does not make the interior light come on where as all the other doors do. Hence I think it is very likely to be a fault in this door.
So if you have the lock noise on turning the ignition then check which doors make the interior lights come on it could be a good clue to the faulty one if any do not make the light work.

My first post on this forum and thanks to all the fantastic contributors. My project 2002 A2 1.4 petrol 82,000 miles has been really fun (only £800 quid on Marketplace) to feed my fiddling habit.
Successful fixes so far -
Glove box light
Boot light
Rear interiour light
Drop links
ARB bushes
Headlight polish and new bulbs
Windscreen polish to remove bad wiper scratch
Fuel filter change
Oil change
All air filters
Spark plugs
Boot struts - tried several but only stabilus seem to have built in dampers at top of travel.
Reverse light bulb.
Bluetooth FM adaptor from lighter socket and mod socket to be only live with ignition on with a fuse re route - works great.
Lots of cleaning and polishing of course.
So now cost a total of £1,300 plus the usual on the road costs. Great way to have fun and a nice car to drive. I'm sure there will be plenty more interesting jobs to. Come.

 

[3wheeler]

I also have now stumpled upon this thread, and think this is exactly what inflicts my car too- I have gone through many light switch presses, and still wonder at the reason for my drivers-side map light working under certain conditions on my replacement OSS console pack, but the rear unit only works as previously stated, so out comes the soldering iron! What I love is that these cars are basically so good, its the little niggles that are left to fix (famous last words..)

 

[Ami]

I also have now stumpled upon this thread, and think this is exactly what inflicts my car too- I have gone through many light switch presses, and still wonder at the reason for my drivers-side map light working under certain conditions on my replacement OSS console pack, but the rear unit only works as previously stated, so out comes the soldering iron! What I love is that these cars are basically so good, its the little niggles that are left to fix (famous last words..)

Before taking it all apart just waggle the cable connecting to the micro switch, on mine it was the loom, replaced it & all good.

 

[3wheeler]

Before taking it all apart just waggle the cable connecting to the micro switch, on mine it was the loom, replaced it & all good.

Thanks Ami- I simply removed the rear lamp unit and soldered this joint in question. The whole process took 10mins and problem solved!

 

[Ami]

Thanks Ami- I simply removed the rear lamp unit and soldered this joint in question. The whole process took 10mins and problem solved!

Good job, result