OK
Trunk lights do not light. Bulbs are good.
What actuates the lights? Button on truck lip? Built in sensor? Fuse????? Lighting?
This is just a minor thing but it would be convenient in the dark.
Any help appreciated.
Rob

 

radjag1,

Well your query reminds me of my trunk light fiasco. I finally got them to work but, to this day, I'm not sure what I did that actually repaired them. So to your question. Here's an excerpt of the Electrical Guide for my Gen1 car.


As you can see the trunk lights are switched and have a diode, in the circuit, and it's a BPM controlled shared ground. Common problem is the microswitch, attached to the latch, goes bad. The diode also is a common Ford part.



Wiring is through the right wall of the trunk floor (not the lid hinge) and it's easy enough to strip the rear trunk plastic trim sill. There are some Youtube videos detailing the operation. Be very careful of the red tab on the latch mechanism as it's a permanent lock. DO NOT MESS WITH IT.

 

so....I find this diode IN the trunk near the latch? You said NOT in the lid though.

 

Radjag1,

In my MY99, the diode is in the wiring circuit above the battery.

The common problem is the microswitch attached to the latch. Rear trunk trim has to come out to reach it.

 

radjag1,
Check out this vid on youtube to solve issues with XK8 Trunk lights.

 

Great help and video.....Thanks

 

Without getting in depth, I find I have power to the one wire at the light plug. So now I'll get my hands dirty and tear the trim panel off and dig out that micro switch. I found a couple on Ebay for $70.
Any used ones out there??

 

radjag1,
John from 'ToTheGarage' on YouTube also did a Video on access to the trunk latch which reveals the lamp micro-switch and he explains the red selector which that 'DavidYau' mentions above. Be careful not to push down the red selector !

 

Hi,
I took the trunk latch off. I took the switch out. I closed trunk but remote would not open trunk. Put switch back and trunk openned with remote again. So if that works then is it the Diode that's bad? What does the diode do?

 

Radjag1,

You’re following in my past footsteps where I was exactly in the same situation. Confusing eh?

Did you see boot open warning on the dash when you tried with the trunk latch microswitches removed? My remote also stopped working with the switch off the latch.

Bench checking the diode is easy with a multi meter. Should have continuity one way and none the other. 2 min job and you can’t connect it wrong due to shape of the connector.

Remember it’s a BPM controlled ground as there’s always 12V on one pin. Trouble is the ground seems shared with lots of other things.

I had a strange case where one trunk light bulb was distinctly brighter than the other so I got the two bulbs from my donor car and put them in. I was also working on the sun visors at the same time, and this too seems to be on the same BPM circuit on my 99.

I put the switch back on the trunk latch, made sure the plastic housing clipped firmly in place and back traced the pins to make sure the microswitch’s circuit opened/closed with the latch.

With the new old bulbs identical, sun visors fixed, microswitches ok, new diode, my trunk lights came back to life.

Not sure this helps.... but I recall the fiasco well.

 

Thanks
I will order the diode. It looks like it's also used on Transit vans and Focus. It has the same part number.
Rob.