1988 XJ6 Vanden Plas. RH rear brake light/turn signal stopped working along with upper brake lights. Tester shows current coming in on all pins from wiring harness to the 4 bulb circuit board. All fuses in the front panels up front are good. Checked all bulbs.

Interestingly the running light works. The light bulb circuit board is good, as I tested it on the working LH side. I took the LH bulb circuit board and plugged it into wiring harness and got nothing.

I have disconnected and cleaned all of the sockets leading to the turn signal blinker box in RH trunk. Still getting Circuit 1, Circuit 2 and bulb failure error messages.

Blinker box in trunk was making its normal clicking noise with circuit board plugged in - sans light bulbs. Plugged bulbs back in and heard a static type noise from RH side of trunk and then blinker box stopped clicking. After unplugging circuit board, blinker box began clicking again when car was restarted.

Is this a relay problem? Not sure where to look next...

 

HI,

Switch the BFM's (Bulb Failure Module) around and see if the problem follows the BFM. Most likely you have poor solder points the RH BFM. It's a simple fix requiring you to open the bad BFM and re-solder the points. They will be obvious, usually discolored or have light rust residue on the points. This is a common issue with the 88/89 BFM's. The BFM's are the square boxes (either silver or black in color) on each side (adjacent to each rear light assembly) that supply the circuit where you plugged the light circuit boards into, just follow the light circuit board connection back to the BFM.

If you have more questions, post up again. Hope this helps, good luck.

Rob Evenson
89 XJ40 123K
Mobile, AL, USA