MOT fail...Only one sidelight when ignition off - FIXED!

[clubsport78 0]

Hi All,

 

My C has just failed its MOT on just the one thing...sidelights :mad2: . The sidelights all work fine when the ignition is on as do dipped and full beam. However when the ignition is off and you leave the lights switched on, only the offside light stays lit but there is nothing from the nearside light, hence the fail. I have just changed the bulb (the MOT place were going to do it for me and pass it, but had none in stock :epicfail: - It is a small 4w type?) and it has made no difference. The indicators are also in the neutral position as I initially thought it was a parking light type issue.

 

Has anyone got any ideas???

 

The lights are a bit of a pig to get to on one side due to the air box, my only thought is to check the other side as it could be the bulb has always been the wrong type and is causing the fault? :shrug:

 

Failing that I think I will need to check the wiring and see if the voltage is dropping on the cable that feeds that bulb when the ignition is off. Could it be that the headlight switch is causing the problem as I know they are a potential weak point?

 

Cheers.

[clubsport78 0]

Bump.

 

Any ideas?

 

Oh and the heater matrix has just gone pop. What a fun day I am having!

[Critical_Mass 10]

Do you have an aftermarket wiring loom fitted? If so it could be one of the relays.

 

To get to the bulbs, you're best off removing the headlight completely - 2 screws on top of the slam panel, but there is a 3rd screw holding the headlight in, you have to peek down a hole in the slam panel to see it, a long screwdriver will reach it. Does the sidelight work when the ignition is on??

[mattnorgrove 0]

If as you say they both work fine with the ignition on, then the bulb and switch must be ok.

 

Does sound more relay related.

[Mawrick 0]

Are you sure the car isn't supposed to do that ?, IIRC the VW's will turn down to parking light when you turn of the ignition, and I think on some cars only one light will be lit. (My Passat does that too, can remember with the Corrado as it's in parts), but my Passat was just through MOT, although it failed on some things this was not mentioned as a problem.

[clubsport78 0]

Cheers for the replies guys. Yep all lights work fine when ignition on...

 

As far as I know, there is no updated loom fitted (only had the car 7 months). Will check on the relays though...

 

Yes I just thought the one light was a normal 'VW thing' as it has always done it. MOT guy reckons both should be

lit though .. If someone could check on a working Corrado I would be grateful to get a comparison.

 

If I can't get to the bottom it, I think linking accross a bit of wire from the working drivers side one may be a way to get it through?!

[Critical_Mass 10]

If its not just the parking light (i suspect its not just that). First thing to do is put the working bulb in the other headlight - Remove the lights completely, makes it alot easier. If the light then works, you know its either the wires inside the headlight OR the standard wiring loom.

[Guest]

all marker lamps (front side lights and tail lights) should be lit when you operate the headlamp switch, even without the ignition on

 

 

sounds like someone has taken a live feed, off one of your side lights maybe? to power something else? permanent live for a stereo maybe? gonna be something like that for sure, especially as its not ignition related

 

maybe worth trying another headlamp switch too as they are common for faults

[clubsport78 0]

All fixed now. There was a brown wire which had come off the terminal next to the terminal for the grey and black wire going to teh sidelight bulb holder.

 

I took the working light out and it became apparent that the other side was missing the cable. Took the other light out, fished around for the offending brown lead, fixed it to the terminal and hey presto, it is working again! Hopefully I will be able to get a nice green slip off the MOT man :clap:

 

One further issue, just put the light back in and noticed a white VW label floating around inside the lens :censored: , which must have come lose when I took it out. Back out the light came and lens off to remove it! All back in and working now though.

 

Just the heater matrix to do next! Something tells me that isn't going to be quite that simple...

 

Cheers for your help and advice guys. Especially where the screws were to get the headlights out. It would have taken me ages to find that hidden third screw . It's easy when you know how! :salute:

[Critical_Mass 10]

All fixed now. There was a brown wire which had come off the terminal next to the terminal for the grey and black wire going to teh sidelight bulb holder.

 

I took the working light out and it became apparent that the other side was missing the cable. Took the other light out, fished around for the offending brown lead, fixed it to the terminal and hey presto, it is working again! Hopefully I will be able to get a nice green slip off the MOT man :clap:

 

One further issue, just put the light back in and noticed a white VW label floating around inside the lens :censored: , which must have come lose when I took it out. Back out the light came and lens off to remove it! All back in and working now though.

 

Just the heater matrix to do next! Something tells me that isn't going to be quite that simple...

 

Cheers for your help and advice guys. Especially where the screws were to get the headlights out. It would have taken me ages to find that hidden third screw . It's easy when you know how! :salute:

 

No worries mate, glad you got it sorted :D