Lately, when I push on the brake (thus activating the brake lights) the front parking lights go out. When I release the brake, they come on again.

Probably not an uncommon issue on a 30 year old Jag. Thought I'd check before I head off in the wrong direction trying to diagnose it.

Thanks,

John
1987 XJ-S V12

 

John,

I'd check the earth points on both the brake lights and the front sidelights. Your symptoms are typical of weak earth where the circuits seek an alternative path to earth.

Paul

 

I was wondering as much. I thought I'd cleaned every earth point imaginable when I redid the wiring a few years back, but maybe I missed one (or ten).

Thanks!

John