I have a 94 xjs. I am having trouble with the right headlamp (bulb is new and checks ok) The right headlamp does not illuminate when I lock car and set alarm. When car is running and low beam headlights are turned on, right headlamp stays at parking headlamp illumination. Headlamp does function at full illumination when highbeam switch is active. Is this due to a faulty Headlamp controller DAC6902? Does this controller handle the logic for low/high beam? Or is this likely a loose connection? The problem is intermittent.

Thanks

 

sconard, my experience with the headlight logic module went like this. I had low beams, and could flash the high beams, but would not stay on bright, except, maybe once out of a hundred trys. I think it only controls the high/low operation, and not the individual lights. Sounds more like grounding, connections, or maybe a faulty fuse. The nice thing about Jaguar, they no longer make DAC6902 incase it turns out to be the problem. I had to check all the advertisements for parts cars. Finally checked the normal parts houses, some have parts cars for used parts, and got lucky.

 

So if it is only one headlight, it is not the controller.
Can anyone else confirm this?

Thanks

 

As it turns out.

I replaced the bulb with a new bulb from local parts store. Bulb did function and did test ok. When failure occured again, (one week) I replaced the three connector harness at the back of the headlamp. This did not help. Then I took it to a shop for oil change and had them look at the headlamp issue.

The first thing they did was insert a new bulb (the second in as many weeks) Voila. Both headlamps have been functioning ever since.

Apparently the new bulb fried not long after install. I suspected electrical issue as it happened so close to the last one burning out. I also expected the new one to burn out soon after install due to surge or whatever caused the first to go. This was not the case and the new bulb has been fine for the last half year.