Interior lights are out. 05 Passat 1.9 TDi

[JoeSoap]

Hi all, I have an electrical problem. I have kept an eye out for water ingress (known issue I believe) on my 05 plate 1.9TDi Passat since I owned the car.

I have the following issues-

Are working- The 2 red LEDS on front courtesy light assembly, rear cabin courtesy lights, front door interior opening lever illumination.

Are not working- Boot interior light, glove box light, front door puddle lights, front interior light cluster and the front map reading lights.

The fuse is fine, I've checked it, any clues please? I don't think it's the water ingress issue (I hope anyway)?

[martin1810]

Check the wires to the ccm under the passenger carpet. These lights are linked via the ccm but as most of the ccm functions are ok, the ccm should be ok. It could be damaged wires or a loose connector.

[JoeSoap]

Check the wires to the ccm under the passenger carpet. These lights are linked via the ccm but as most of the ccm functions are ok, the ccm should be ok. It could be damaged wires or a loose connector.
Thanks for quick reply. I'll look tomorrow.

[JoeSoap]

Well, I've just checked it out. The wiring and CCM are bone dry, in 100% as new condition. I have checked the connectors and are all sound. Unfortuantely no change. I'm afraid I haven't a clue what to do now. Any ideas anyone? Thanks.

[STEWY L]

only guessing but that's a lot of lights for one fuse, sure their isn't another fuse
in the dash somewhere(r/h side i believe),or a relay.
by the way, if the INTERIOR lights are OUT,
does that make them EXTERIOR lights?
sorry,
stewy.

[JoeSoap]

only guessing but that's a lot of lights for one fuse, sure their isn't another fuse
in the dash somewhere(r/h side i believe),or a relay.
by the way, if the INTERIOR lights are OUT,
does that make them EXTERIOR lights?
sorry,
stewy.Looking at the book, they're all on fuse 14 (IIRC) which is 10 amp. But seeing as the rear cabin lights, the front cabin courtesy lamp cluster red LEDs and the door handle LEDS are working then it isn't the fuse. I checked anyway. If anyone knows of a relay or another fuse, I'd appreciate it. Thanks.


By the way, groan!

[martin1810]

The following lights are on the same circuits and should be working; Left & right centre reading lights, left & right rear reading lights, left & right vanity mirror lights. Are these ok.
The following lights are related via the ccm and may not be working: Rear left & right puddle lamps, Front left & right puddle lamps, boot light. If any of these are not working it still suggests a bad connector under the carpet. Look for red/black wires.
These circuits don't use extra fuses or relays.

[JoeSoap]

The following lights are on the same circuits and should be working; Left & right centre reading lights, left & right rear reading lights, left & right vanity mirror lights. Are these ok.

In your order- No, Yes, No.


The following lights are related via the ccm and may not be working: Rear left & right puddle lamps, Front left & right puddle lamps, boot light. If any of these are not working it still suggests a bad connector under the carpet. Look for red/black wires.
These circuits don't use extra fuses or relays.

In your order- No, No, No.

Oh dear, nightmare scenario , two possible separate faults? :(

Thanks Martin.

[martin1810]

The fact that two circuits are effected suggests it may be a connector problem. I would look closely at the connectors on the ccm and all nearby connectors. Look especially for any bunch of red/black wires as these will be for the light circuits. Goodluck.

[JoeSoap]

Thanks Martin. I'll have to get the carpet up again it seems for another look. I pushed all the connector blocks I could find together to make sure they hadn't come partially apart. Seems I'll have to go in there again though.

On the bright side, at least the CCM isn't water logged. Cheers for the help. It's appreciated.

[JoeSoap]

Ho hum, carpet and CCM out again today. Close scrutiny of anything with red/black colour, no damage visible. All plugs undone, inspected, reconnected. No sign of any damage or any detioration, all looks like brand new. As a check I've looked at all the bulbs this morning and none are blown.

I'm guessing now that either there's a partial electronic failure of the CCM (no visible damge at all) or a wire is broken inside the insulation and is not visible. I'm afraid now it'll have to stay like this. Sad, but the car runs OK. What a shame, it's the very first fault the car has ever had.

[kenney]

Remove the insulation tape on the CCM harness,from the connector,and about 40cm,there are joints in the harness,which corrode

[JoeSoap]

Remove the insulation tape on the CCM harness,from the connector,and about 40cm,there are joints in the harness,which corrodeCheers Kenney, yes I found them, they're in perfect as new condition. I bundled the harness back together with tie wraps rather than tape. It's staying as it is now I'm afraid, sad, but it isn't life or death that they work. Thanks for the interest and advice.

[kenney]

(Are not working- Boot interior light, glove box light, front door puddle lights, front interior light cluster and the front map reading lights).These items have 2 things in common 1 the CCU and 2 the soldered joint in the wiring harness.Are you sure you looked hard enough as there are,i think 3 joints in that area?Which fuse did you check?

[JoeSoap]

(Are not working- Boot interior light, glove box light, front door puddle lights, front interior light cluster and the front map reading lights).These items have 2 things in common 1 the CCU and 2 the soldered joint in the wiring harness.Are you sure you looked hard enough as there are,i think 3 joints in that area?Which fuse did you check?Hi Kenney thanks. Yes, I have done it twice in case I missed something the first time on Saturday and Sunday. My money is on a dry joint or a component failure on the CCU now. I took the binding off the harness and was surprised just how good the condition is seeing as every picture I've seen on the web shows it badly corroded. I put the harness back together with a bunch of cable ties rather than tape as it's neater. I have been paranoid about keeping water out of there though and it shows, it's very clean under the carpet, like new. Fuse 14, swapped out to a new one, no change. Thanks for your interest, it's no big deal really, the car runs OK. Cheers.

[kenney]

That is the wrong fuse,fuse 6 is the one you should look at.;)

[JoeSoap]

That is the wrong fuse,fuse 6 is the one you should look at.;)
Fuse 6 is fine. Thanks.

[IDIY]

(Are not working- Boot interior light, glove box light, front door puddle lights, front interior light cluster and the front map reading lights).These items have 2 things in common 1 the CCU and 2 the soldered joint in the wiring harness.Are you sure you looked hard enough as there are,i think 3 joints in that area?Which fuse did you check?

Thanks for your info on this problem my 99 TDI Estate had faulty joints in the the wiring loom, very slight damp feeling on the old insulation but no evidance of water damage to CCM. Resoldered all the joints and now working fine - it beggars belief how a quality car should have joints in a wiring loom - no doubt built obselence by VW