I have a 1988 Jaguar XJS V12 5.3L coupe. I've noticed that when I turn on the headlights the high beams are on, stays on and won't turn off. What steps can I take to resolve my issue? All suggestion welcome.

Thanks,

Marcus

 

Start by looking at the headlight relay, under a plastic cover in the engine bay just to the rear of the LHS headlight nacelle.

 

I've replaced the Jaguar XJS Hella 4RD001836-05 12V Healdamp Dip Relay under the black cover and got the same results.

 

Have you got the headlight circuit wiring diagram?

 

There is relay (I believe it is a silver box) that controls the headlights. Unplug it and see if the lights go our.

 

this is what I have.

 

The attached pdf is what you need.

 

This obviously isn't something new since the original inquiry is 4 years old.

Have both sets of lights 'always" come on ever since you owned the car, or was it something that cropped up later (4 years ago).

If its always been that way, someone may have rewired things prior to your ownership.

Doug