rear fog lights not working???

macerena

Regular Member
Hi all,
Not posted on here for a while but having issue's with the rear fog lights on my veccy b. :(
Its the CDX model with the hid lights on the front.
When you press the light selector for the rear fogs it illuminates the little light for them on the dashboard but the lights on the rear cluster do not illuminate. i have changed the bulbs and had most of the fuses out of the fuse box and refitted them again in case of dodgy connection. does anyone here have any idea's on a way forwards.
Obviously i don't fancy going to the stealers for there diagnostic inspiration at the daft prices but am willing to get stuck in and get my hands dirty again. Mot is at end of Feb as well. Failing that and if the light switching unit is duff can you bypass this with a seperate switch for the rear fogs and still pass the revised new Mot,
Many thanks again for your imput,
Cheers,
Andy
 

Daz

Former Staff
Senior Member
not gonna be a fuse if the little light is coming on in the switch, when u turn the switch on can you hear the relay clicking?
 

macerena

Regular Member
Relay???. Could'nt hear anything this afternoon when i had a play but i had the engine running and kids were playing near me so was'nt the quietest.
Do you know where this relay is per chance. I'm not into electrics that much, more mechanically minded but am happy to swap out electrical components though.
Cheers for the quick response.
Andy
 

Daz

Former Staff
Senior Member
gonna be in the fusebox under the dash... from memory its gonna be one of the small grey or black ones...... if nothing is clicking in there when u on/off the switch, try turning the front fogs(if you have them) on and off and listen for that relay, the rear one is probs next to it then....
 

macerena

Regular Member
Hi again all,
I have had a play with the light switch and felt around the relays with engine running and not running. On both occasions i could feel & hear the front fog light relay making and breaking. When trying the rear fog which have the problem the switch was noiser than anything else and i could not feel any relays making or breaking and obviously the rear fogs did not illuminate. With the engine running when you switched on the front fog lights you could hear the engine note change as the extra loading was fed through the alternator but nothing at all with the rear lights.
So to conclude, does anyone have a good number for the rear foglight relay for a vectra 'B' CDX model with the Xenon lights at the front. (Don't know if the Xenon lights make any difference but thought i should put in all the details). Also does anyone know the precise location of the relay before i prob have to go to the Stealers for them to supply the part,
Many thanks again,
Andy
 

Daz

Former Staff
Senior Member
Got a fuse box out of my old vec here, will dig it out 2moz ,,, shud be a relay inthere too
 

macerena

Regular Member
Well,
i finally got onto the car with a multimeter today,
Checked the light clusters and the connections as well. also checked the loom termination plug at the clusters and no power to either rear foglights still. Managed to get a new relay from the local stealer as well and changed that just in case. Ended up still not working. dunno..
I then unhinged the fuse box and checked the wires behind. When the rear foglight switch is not selected there is 12v+ at the top spade connector and nothing at the next one down. When you select the rear foglights on you get the symbol on the dashboard and at the one below the top one you get 12v+ for both wires and nothing at the rear clusters. Does this mean that there is a break in the cables to the rear clusters or do these two cables feed the main selector switch. If the cables feed the rear cluster then i guess i will end up running two new cables to the rear clusters to restore functionality to the rear fogs again.
Sorry about all the words and hope one of you more electrically technically minded people can advise me further,
Many thanks,
Andy

Also the dealers could not advise me as to which relay i should have been looking at initally but eventually managed to redeem themselvs after 30minutes. they also suggested i should pay £70 to plug it into the tech 2 machine for daignostics which i declined.... Mad or what and they are meant to be the subject experts...................
 

jwalker

Senior Member
I have exactly the same problem, MOT due next month as well!

I think I know what the problem is, I will post it up here if it works but remind me if I forget!
 

macerena

Regular Member
Any joy with your remedy with the rear fogs jwalker?. Mot due very shortly and hope for no nasty big bills so if i an sort out first in prep then worth doing. Getting it up on the ramps in work in the next couple of weeks as well to have a go over underneath prior to the big day.
cheers,
Andy
 

jwalker

Senior Member
Yeah got mine sorted, really straight forward.

In the boot, remove the rearmost trim panel (between the rear lights) and you will see loads of wiring. Bridge the two black/blue wires together, job done :D

Mine wasn't working because the monkey who fitted the towbar had left a total mess!
 

macerena

Regular Member
Sounds like yours might be a different fault to mine then as i don't have a towbar fitted and assume the wiring behing that panel is not a complete nest.
I will try and check tonight just in case the previous owner had been fiddling with the wires. Car has aftermarket reversing sensors so wiring around there has been disturbed at sometime,
cheers,
Andy

*just had a look behind the trim panel between both rear lights and it is a snakes wedding in there. lots of the quicklock connectors and tangle of wiring comming off a o.e.m plug by the look of it?. not sure what that means or is it vx doing a quick fix to get something fixed again. i take it you mean the wires with the black shaething with the blue line in it. if so there seems to be two bullet connectored together and another dissappearing somewhere else*
 

jwalker

Senior Member
There is a towbar connector/socket type thing behind there anyway, regardless of whether you have one fitted. I haven't got the wiring diagram to hand, but that is where your problem is likely to be.

The black wire with the blue line is the correct one, mine was a similar mess and all I did was look for two wires and tried them together. One comes from the relay at the front, so push the switch and check each one for power. Assuming you have power, joining this wire to another one of the two with the same colours should get the fogs working again
 
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