2003 Jaguar S-Type 3.0

Brake Light Issue – Need Advice



I’m dealing with a brake light issue on my 2003 Jaguar S-Type:

• The right rear brake light is dim and sometimes doesn’t turn on at all.

• The third brake light flickers on and off.

• All other lights on the right side (turn signal and parking lights) work fine, except the brake light circuit.

• I’ve already replaced the bulbs and cleaned the housing with electrical cleaner, but there’s no difference.

• The left side works perfectly.

• Checked the ground near the ECU box (right rear side) and it seems secure.

• Tested fuses in the trunk compartment with a test light, and they’re all good.

• Voltage readings seem normal.



Could this be a wiring issue, a faulty housing, or something else? Any advice or suggestions would be greatly appreciated!

what I need to buy a new housing picture above

 

I am curious if you also get an occasional warning on the dashboard that the BRAKE LIGHT FAILED? That's a problem I've had, and I wonder if it is similar to your problem. It is a random error message, and in fact, the brake light seems to work normally most times.

 

You mentioned that you cleaner the housing with electr. cleaner. To me, it is not clear, what exactly you did there: The housing is the plastic part...
A possible reason for your problem - and you did not write, if you took care of that - are corroded contact surfaces.
Have a very close look at the contact surfaces in that housing: Are they clean? Are they where they are supposed to be or are they bend out of the way?

If the contacts are not clean: remove the oxidized layer with some kind of scraping tool (screwdriver). If that solves the problem, you found your problem. But if it was, it will oxidise again.
Two suggestions there: 1. Use a soldering iron and place a blob of solder onto that contact. Sometimes though that does not work, as some metals do not want to accept "blobs of tin". 2. At least use Electric contact spray CRC 2.26

 

Please see these threads:

https://www.jaguarforums.com/forum/s...llights-53056/

https://www.jaguarforums.com/forum/s...ystery-219022/


In both of those threads, strange behavior of the rear lighting was caused by a seemingly unrelated fuse. How this happens, I can't quite say. All I know is this strange phenomenon has been observed multiple times on the forum.

This thread had a similar problem, but unfortunately was never resolved:

https://www.jaguarforums.com/forum/s...-lights-284328

Lots of good info there, however, including the correct part numbers for the bulbs.

 

The first thing to try is to swap the bulbs from one side to the other and see if the fault changes sides as well.
You also need to make sure there are no aftermarket 'additions' to the wireing, like a reverse camera, tow bar or any other electrics in the boot/trunk.
If there are any disconect them and see if the faukt goes away.

When faukt finding it is wortyh knowing that these cars use a switched earth system not a switched live, the 12v is constant.

 

Coukn't agrie moer.