Hi,
I am in the process of moving and packed all my Jaguar books.

My high beams started to work intermittently and now they do not work at all.

Where should I start looking? As always, I suspect a relay but don't know which one.

Thank you,
Jomo

 

I’d check the earths

 

These should help.

 

Not sure what your model year is, but for the later years, there is a specific headlight logic relay that is a common failure. DAC6902

 

The car is a 95 xjs convertible (its in my signature).
Does anyone have the wiring diagram for the DAC6902 relay?

 

It's in my previous post.

 

it’s not a simple relay. If you search the forum for that part number you will find a lot of good info.

 

I only saw one pdf initially.
This is just what I need.
Thanks!
Jomo

 

Yes, I know exactly what part you are talking about. I wanted the schematic because it was not a simple relay.

I easily opened up the module tonight and it looks brand new inside. Both relays do work. I checked the resistors and they too are fine. I could not check the diodes or capacitor--although the capacitor did not seem to have any leaks. I did check using a meter for cold solders. That is, I checked for continuity from the solder to the part that was soldered. All seemed fine there. Does this method work that I used?
I am having my doubts that this module is bad.

Jomo

 

Your symptoms are common, and the replacement of that part is a very common solution. Not sure I've read anyone having your same problem that wasn't solved by replacing the part.

 

Armed with the schematic for the headlight logic relay given to me by petemohr I found a short in the wiring that fixed my issue.

Thanks for everyone's help.

Jomo

 

That is great news!!

Could you share any specific info that might help someone else in the future?