Hi, Dave here from California,
im pretty sure this topic has been talked about, but my rh rear light cluster is not right. I get a “ check rear lights message” every time I hit the brakes. When I check the lamps with the car running and the brakes applied, brake lights come on sometimes, not always. If I put on the turn signal the brake light blinks dim and the running lights are on but dim. All bulbs are good with good connection. Signal lights blink faster than normal with brake pressure. I’m confused. This started out of the blue. If I pull the light cluster out all the lights seem to work correctly, bad wiring? Bad grnd? Any help would be awesome.

Helps to know what year and model you have. There are some differences across the years in the light cluster and monitor circuits.

If you haven't added the extra ground strap yet, it would be a good time to do that.
Do a search, some good pictures on DIY.
You can look at the plug and see if the black wire is melted, way too small for all the lights in that circuit.

I'll second adding the additional ground wire

Thanks for the suggestions. I have a 2000 XKR, with 50K miles. What an absolute joy to drive...,I do have some preventative changes coming up (timing chain tensioners) etc. but until then. Vroom 🏎

Off the original topic, but you may want to replace the tensioners before vrooming much. Unless you know upgrades to the contrary, someone pulled the pin on that grenade 20 years ago, and it's long overdue going off and taking your engine with it...

To reinforce this, I intend to alert you herein..at 51,719mi (4-26-10) my now 2001 XK8, built Jan 2001 had a chain guide failure. The bill totals $9398.04.

Parts list total $3572.73 labor $4944.81, outside services $550. Only one side had to be tended to...I think today this totals our typical vehicle...

No disrespect here, I recall a line in Dirty Harry film, "Are you feelin' lucky punk?"

Thanks for the advice. Will be inspecting the engine soon

Sure sounds like the light issue is the ground wire. See post #26 https://www.jaguarforums.com/forum/x...d-35083/page2/

I second and third the above mentioned tensioner and ground wire recommendations. Bought my XK8 (second owner) at 55,000 miles and first thing I did was replace tensioners, guides and chains. Amazed that they hadn't failed. Check that as soon as possible. The added ground wire to the tail light housings solved all my tail light issues, quick 15 minute fix.