C5 rear foglights not working

THELABMAN · Post by **THELABMAN** » 23 Oct 2010, 13:43

Hi Folks,

I've had my C5 for a few months and it was only with some bad weather recetly realised that my rear foglights aren't working, the fronts are fine and the warning lamp lights in the dash but no rear lights...

The 1st thing I checked was the rear lamp assembly with a test lamp and whilst I've power going to all the other rear lights there is nothing going to the foglamp circuit, I chcked the fuse and it's fine too and not blown.

My car is fitted with a towbar and dual electrics, a search on here suggets that a common problem is a pin in one of the sockets stuck in but everything seems fine from what I've seen.

Another sugestion seems to be something about a relay being removed to stop the cars lights dazzling the driver off the caravan/trailer that is being towed but I can't find anymore info on where to look for the said relay.... can anyone on here help or offer any other suggestions, it's just with winter coming I'd realy like to get them working and obviously they need to for the MOT but it's not due to April though...

Car is a 52 plate 2litre HDI hatch...

Thanks in advance

Peter

THELABMAN · Post by **THELABMAN** » 25 Oct 2010, 17:04

Nobody have any ideas's then what the problem is likely to be ........

dnsey · Post by **dnsey** » 25 Oct 2010, 18:40

Is there power at the fuseholder?

JohnD · Post by **JohnD** » 25 Oct 2010, 19:25

Have you got a Smart 7 relay fitted for your 12N socket? If so maybe there's a malfunction on the foglight wire. Thinks the caravan socket is plugged in so keeps the car's rear foglights off. If you've got a fuse in the line from the battery, try removing it to disrupt the supply to the Smart 7.

THELABMAN · Post by **THELABMAN** » 25 Oct 2010, 19:39

Hi Folks,

I never thought to check supply to the fuse holder dnsey, not sure how easy it would be to get the test lamp in there as the rear fog light fuse is squeezed in right at the end of the box up agains the very edge of the opening, it's a right job even trying to get the fuse in and out...

The towbar was fitted when I bought the car JohnD so I've no idea how it's wired up or where a relay would be located to check... it certainly doesn't appear to be inside the hatch area or spare wheel well unless it's hidden behind the panels. The battery wouldn't turn the car over this morning, typical 1st cold morning of winter, and when I'd the cover off at the shop getting a new one I couldn't see any additional wiring running from the vicinity of the battery area that didn't look as if it was meant to be there from scratch...

Peter

THELABMAN · Post by **THELABMAN** » 26 Oct 2010, 12:22

Hi Folks,

Managed to get a dry spell there between the showers and as suggested by dnsey I've checked the power to the fuse for the rear fog lights and there is power going to it, I've also changed the fuse for a new one although I can't see anything wrong with it but still no rear fog lights....

That to me only leaves the relay as suggested by JohnD as a possible suspect but I still can't see anything in the hatch area. Before I start trying to figure out how to pull the interior trim off without damaging anything does anyone have an idea where it may possibly be located to narrow the field slightly, Im assuming near the rear light clusters to pick up power for the sockets but I couldn't see anything when I'd the rear lamps out....

Peter

JohnD · Post by **JohnD** » 26 Oct 2010, 15:29

THELABMAN wrote: does anyone have an idea where it may possibly be located

Mine is the estate version so I've located mine in one of the two 'cupboards' set into the linings.

dnsey · Post by **dnsey** » 26 Oct 2010, 16:45

Have you looked under the boot carpet? There's quite a lot of lost space there, very useful for hiding gadgats - I put my reversing alarm control box there.

THELABMAN · Post by **THELABMAN** » 26 Oct 2010, 17:56

Hi Guys,

It's been pouring down here all day so haven't been able to look at anything since I got the fuse box box checked, hopefully if it's a bit drier tomorow I'll try and see what's lurking under the carpet... mine's a hatchback so there are no storage areas in the flanks to check... having said that SWMBO has a fUll day planned tomorrow so I may not get time for anything

Peter

Post by **myglaren** » 26 Oct 2010, 18:02

I hate to say this but - you are turning the stalk twice to operate the foglights?

Mine would first turn on the rear foglights, then the front ones.
You can change this order with a Lexia but mine did it all by itself one day

THELABMAN · Post by **THELABMAN** » 30 Oct 2010, 22:59

Hi folks,

Yes myglaren the first position brings on the front fogs then the 2nd should bring on the rears, the warning lamp in the dash lights up but no rear lights come on...

I managed to get a dry spell folk to get all my junk out the back and get the mat up, the hatch only has the spare weel well and nothing else to hide anything in.

I removed the plastic cover that runs along the inside of the sill and I can see where a wire looks as if it comes up from under the car, presumably from the towbar, and appears to be spliced into the main harness running along the back of the car but nothing that looks like a relay or a fuse holder....

Getting to the stage where I think it may have to be taken to a garage to have them look into it for me....

Regards

Peter

dnsey · Post by **dnsey** » 31 Oct 2010, 01:29

Has the towing socket got power at the fog connection (pin 2)?

THELABMAN · Post by **THELABMAN** » 31 Oct 2010, 22:38

Hi dnsey,

I don't know which of the two sockets are used for the lamps or which pin is number two as I've never towed or hitched anything to a towbar.... would it be a case of just turning the switch on the stalk on then check each pin with the test lamp.... I don't have a volt meter or anything just one of the screw driver type 12v test lamps with a wire and crocodile clip to attach to an earth point.

Peter

Post by **quintet** » 31 Oct 2010, 23:14

The black socket will be the main lighting socket for a trailer/caravan, the other socket (usually with a white cover) is for reverse lights & power feeds for anything you should wish in a caravan (eg extra battery, fridge/freezer etc), if the car wasn't used to tow a caravan previously then it may well have only 3 wires going into that particular (white) socket, anyway its the black socket you need to concentrate on. Can you tell which make of tow bar is fitted? (look for a brand name on the actual towbar) what does the wiring look like in the boot area, genuine citroen tow bar wiring plugs directly into the cars original harness so it should look neat & have non of them god awful scotch-locks connecting the wiring (although ironically they were supplied in the genuine kit!), my point is the black socket on an original kit has a cut off lever built into the socket to 'knock off' the fog lights when a trailers socket is plugged into it. This tiny lever is located within the left hand side of the socket and once pressed it cuts the power supply to the fog lights, have a look at this little lever & see if its jammed, the lever is connected to a 3 pin switch (only 2 wires used though) & it might be worth checking the condition of it and it's wiring. You can easily test the feeds from the socket using a basic test probe & simply switching each light on in turn & most sockets of a half decent quality have the actual pin numbers on the inside of the cap.

THELABMAN · Post by **THELABMAN** » 07 Nov 2010, 07:32

Hi Folks,

Sorry for the delay in getting back but between the horrible weather, my shifts and taking the wife to hopsital I only got a chance to check things yesterday at work on my meal break.

As far as my simple test lamps is concerned I don't seem to have any power to any of the pins on either socket, with lights on or off.... this is with the crocodile clip attached to one of the towbar mounting bolts which I'm assuming is earthed as it passes through the car body.

I can't see any name on the towbar and the wiring harness that appears to come from it is attached to the main harness running across the back of the hatch, whether it's spliced in with scotch-lock connectors it's hard to say as it's pretty well all taped up and wrapped in sheaths of insulating tape and I didn't have the time to start trying to pull it apart... that and I don't want to end up with no rear lights on the car at all.

So I'm afraid short of getting a garage/ auto electrician to look into it I'm at a loss as to where to go next...

Regards

Peter