My left rear brake light only lights up during the day at night time it does not light up. 2003 Jaguar s-type r 130,000miles

 

when you say it doesn't light up at night time, do you mean when you have your lights switched on ?

 

Yes when the lights are on it tailights on but when i brake the whole taillight goes out

 

I'd be checking earths in the tail lights.

 

ok, you could try the usual, check the is no water in the boot affecting the Rear Electronic Control Module (RECM), and that you have no loose, damaged, corroded wires or connections between the RECM and you lights.

Hope this helps

 

+1 and also whether any of the bulbs in the same circuit are the wrong type despite fitting (fairly common).

 

Wrong bulb or bad bulb. Easy fix and low cost. Get a list of all the bulbs in the tail lamps, and replace all of them. Should be had for less than $30.00. That is what I did. I know you expect the lamp warning to tell you but sometimes it doesn't. Be careful not to short the circuit on the body of the car if you change them while the battery is still connected. I speak from experience.

 

Have to agree thats where I would start

 

It is a bad ground. I've seen this many, many times with various trailer lights, why would a car be any different?

 

Thanks for the responses i have my eork cut out for me. Also at idle my car shakes a good bit and restricted performance pops up multiple times i was told i have a clogged cat and didnt know if that could cause the problem

 

Could be cat, could also be several things... plugs, coils, vacuum leak, dirty air or fuel filer, injectors, MAF, or even a air leak from a crack or not properly installed air box.... lol A bunch of little easy to fix things.