Looking for some advice - or the name of a good exorcist. I think the left high beam headlight lamp has been out in my 05 XK8 since I bought it a year ago, but I'm not really sure. All of my driving has been in the city or during daylight hours, so it has never been a problem. Today, I was finishing up installing new brake pads to get ready for an extended trip and decided it was a good time to replace the high beam lamps in both headlights. Running a quick test after the change out, I've run into some perplexing issues. With the ignition on, both running lights and the front side lights do come on when I rotate the switch to running lights only. When I rotate it forward to the low beam headlamp position, both low beams come on and the left side running light & and front side light stay on, while the right side running and side light go out. Strangely, both high beam lamps begin to glow.

Now, when I push the (blinker) stem forward to turn on the high beam lamps, the high beam on the right side comes on and the low beam stays on (running and side light stay off). However, the left side low beam lamp goes out and the high beam does not come on (running and side light stay on).

Still with me? Here's something else. When I have the headlights turned off, but I "flash" my high beams (as if signalling an oncoming car), both high beam lamps (left and right) do come on. This works with the ignition on or off.

Any of this make sense? Where do I tape an aspirin to straighten this out? Is there a computer control module for this? Does it need be programmed (or replaced)? Or is my car truly possessed and I must plan to never leave town after dark?

 

Lights illuminating when they shouldn't has in my experience been the result of a bad ground.

 

.... or a faulty switch....

 

Oooooh, now that is a spooky ($$$) thought, (but it makes the most sense). Anyone know how to get to the turn signal/light control switch without removing the steering wheel?

 

RESOLVED! Kudos to mhminnich and to jshaub (offline); they were exactly right. I finally got the time to pull both headlights and ohm their connectors out. There are 2 grounding wires in each of the connectors; one set on each side had .0 resistance, the others had .8 ohms resistance. I searched high and low to find where the wire looms were grounded but could not locate a grounding point anywhere that made sense. With jshaub's guidance, I located the grounding lug just to the right hand side of the radiator (aka F1 on the electrical Ground Point Location diagram) where the headlight loom grounding wire was supposed to be attached. It was bare and even painted over! I knew the car had had some front end damage in it's past so it looks like there may have been some short cuts taken putting it back together. I spliced new ground wires into the headlight connectors on both sides and ran them to grounding lugs. Bingo! Resistance is now .0 on both sides, and both headlights are extremely bright and functioning correctly.

Thanks again to all the members of this forum for the willingness to contribute; you have saved many of us from financial ruin (and sending the Jag dealer's kids to college) with your experience and wisdom.

 

So relieved to see this resolved, but gotta post my thanks to Redline for doing that which we all pine for . . . an OP who sticks at it, then writes up a well structured explanation.

Above all, I liked your tongue in cheek humour throughout. Jaguar poltergeists indeed? You should see what my brood of cats get up to every April 1st. Yikes !!!

Best wishes,

Ken