My 04 xj8's high mount brake light (third brake light) has been acting very strange. When I first bought the car, it was working just fine. Eventually someone told me it wasn't lighting up and I should check it. I checked it and it does light up, but with almost no brightness at all. The leds are so dim you almost can't even see them turning on. Any idea what this could be? Thanks for the help!

 

This issue must be quite unique in that no one seems to have any idea what it could be? I was really trying to save myself the cost of buying a new high mount brake light but at this point it seems like that's my only option. =\

 

Mine stopped working too. I can't find a fault in it other than the LED don't light up even when I jump 12V to them. So I just bought a strip of red LED light at Autozone for like $15. I wired it up using the old connector and it all works fine now. It may even be brighter now. I was going to do a write up soon.

 

I was thinking of doing the same thing! I decided to go with a second hand high mount light because I found one for $20 and I like keeping it original but it's good to know that the autozone method works! Thanks!

 

Got my used light in and presto! Working great now! I guess jag made these lights to fail after 100000 miles or something since I've seen others with high mileage xj8's with the same issue.