My front fog lights and side marke lights are not working on my 1997 XK8. I checked the 15a fuse in the engine fuse box and the 10a fuse in the trunk fuse box and they were ok (owner's manual said these were for fog lights). The actual light on the fog light switch does not light up. The rear fogs work. I've tried turning them on with the car running and the headlights on. Any clues?

I've searched the threads on the forum, but came up with nothing. Thanks in advance for any help!

 

Hi There is a access panel in the front of the wheel wells that unclips.Test the fog light connector for voltage when switched on, if ok then check the bulbs.

cheers Al

 

I have power to my side lights. I still need to check power to the fog lights with the switch on.

My license plate lights and tail lights also don't work. Is there one thing that these are all controlled by or connected to that may be the problem?

 

Yes. For your '97, check fuse #7 in the fusebox on the left (driver) side of the dash, and fuse #17 in the fusebox on the right (passenger) side of the dash.

 

Yes I failed to mention that I did check almost every fuse in every box and they are all good, #7 and #17 mentioned above included. Maybe it's the melted tail light ground I've seen discussed on this forum?

 

Checked the tail light housings and no melting, so I'm really stumped.... Anybody?

 

First check if any relays are mssing: On your '97, check the engine fusebox and make sure you have all 7 brown relays. In the trunk fusebox you should have 6 or 7 brown relays (if there is one missing, it should only be at the bottom of the 'T' configuration of the relays).

If you have all the relays let me know, and tomorrow I will post some tests to see if the problem is the drive to the relays, the relays themselves, or the power circuit controlled by the relays.

 

All the correct brown relay's are there according to the layout shown in the owner's manual. In the trunk, #6 is missing, but the manual says it is a dealer accessory.

 

is your cabin heating working? My front fog lights and heater failed and it was the to do with the back up sounder box failing and (i think) shorting out the former,

 

Yes, heater works.

 

The two also have ground circuits in common.

There is also some interaction in the switch and the fog light override circuits.

You need a circuit diagram(link found in FAQ) and a digital voltmeter. Just a cheap one will do.

Then you need to start tracing circuits.

 

I attached the relay map. Try swapping the front foglight relay with another relay in the engine fusebox as an initial check of your front foglight relay.

Also, I agree with Plums, there is a shared grounding point for those two lights....you need to follow the black wires back from the lamps to the connection point on the chassis to check that.

 

Swapped known working relay for the front fog relay, no luck. Also did the same thing for sidemarkers/tail/license lamp to no avail.

Time to trace the grounds and then learn to use a voltmeter.

I'll keep you all posted. Thanks!

 

If your going to start hunting this may help. If you can't read the attached images then go to the DIY section and look for the jvk1997en pdf. It has electrical schematics for the whole car. Good Luck

 

My front fog lights, front and rear side lights, boot light, front fog light button in the car are all suddenly not working on my 1997 XK8. I've checked all the fuses and they're all ok.

Billy - Did you manage to find the solution to the problem?

Thanks for your help.

 

Yes, here is the order of what I did.

1. Checked all fuses - good
2. Checked all bulbs - good
3. Checked all relays - good
4. Checked grounds - good
5. Checked power to light switch on column - good
6. Swap out BPM, lights started working, bad BPM

You can buy a Body Processor Module (BPM) on eBay for under $200, but make sure the part number and CATS number is the same for your car. I elected to have the dealer do it because I didn't want to take any chances with a used BPM. Dealer wanted $1200 originally, I talked them down to $980. I know it's a lot of money, but I wanted everything to work properly. I heard of stories of swapping out a BPM and the lights working but the car not starting or other accessories not working.

Hope this helps.

 

Thanks for the information.