Help 97 xj6l

All of the instrument lights no longer come on when I turn on the headlights. The speedometer is visible & noticeably dims when the headlights are turned on. I checked the fuses & they are good. After some online reading , I replaced the dimmer switch but that did not fix it. The only other online suggestion I have found is to replace the body control module ( behind the glove box) ??
Any one here have any experience with this issue

Thanks in advance
Mike

 

How many lights are out? Could it just be that a bunch of the bulbs have died?

What do you mean, 'the speedo dims when the headlights are turned on'? It shouldn't be illuminated when the headlights are off.

 

Thanks for the reply Oubada

I should have said the odometer dims when I turn on the headlights, not the speedometer. Not even sure why I mentioned that part because I believe it should dim when I turn on the headlights.
As to the lights, the entire instrument panel is dark, they were all working and then one day they were not so I am pretty sure it is not just the bulbs as it would be odd for them to all go out at once. I can not see the speedometer, rpm, fuel gauge or any other instruments when driving at night.

Thanks
Mike

 

My odo doesn't dim when I turn on my headlights. Now I feel cheated! ... must be a post 1995 modification.

Definitely sounds like a control issue then. If you do pull out the BCM, have a look inside before you get another one. I hear the electrolytic caps in those modules are the main culprits behind failure, and replacing them is much cheaper (ie. >$10) than replacing the entire module.

 

I've never delved into the panel lighting so I may be talkin' outta my hat....but looking at the diagrams I don't see where the BCM has anything to do with instrument illumination.

THe BCM DOES control interior lighting: map lights, door lamps, etc.

Cheers
DD

 

Do you have the dimmer control knob turned past the detent to the maximum bright setting? If so, the odo, radio, etc displays will not go dim when you turn ont he headlights.

If the dimmer knob is at anything less than the maximum brightness setting those displays will dim with the lights on.

Cheers
DD

 

Thanks again Oubadah,

I will try and have a look inside the BCM this weekend and see if the caps look bad. That sounds cheaper than a new BCM.

I will keep you posted

Mike

 

Hi DD & Oubadah

I took out the BCM & the caps etc all looked good, I went on and cleaned all the contacts etc.. but unfortunately the dash lights are still out.

I am thinking about buying a new BCM??

However:

Doug, you said it did not look like the dash lights went through the BCM? so I am not sure if I should buy one or not. Any other thoughts?

Thanks Mike

 

I doubt the BPM is at fault. I have replaced dozens of dimmer modules back when these cars were still coming into the dealer for repair.

The dimmer module assy was the subject of a TSB. Here are some old ones for diagnosis.

bob gauff

 

Hi Motorman

Thanks for the input, I have already changed out the dimmer switch so before I buy another BCM, I will check the wiring to see if there is an exposed wire as described by your 2nd link.

Thanks
Mike

 

hi
thanks to motorcarman for excellent info....i traced the fault to dimmer module and its an easy to change item fitted under steering column...just remove the lower casing... and wiring to rheostat knob switch/loom..and push up on control module.(tight)
then remove module and fit new one...sorted.
the module output transistor fails and lamps inside car glow using battery power leaving a flat battery overnite.
number two fuse in l/h n/s rear footwell is supply 10 amp..u can remove this as temp measure to use car but the instrument lighting will be off!!!!.
see motormans reply for extra info..
thanks motorman.

 

Hi there,
So where exactly is the dash light dimmer switch? Can you attach a photo?
New to my 1997 xj6 VDP.
All the best,
Ted

 

on the steering column as the small kmob . there is a override feature for full brightness

 

Thanks Parker 7.

Ted