Everything else works fine. Did all the normal things, new bulb, checked and cleaned contacts in socket, checked for continuity of wire to from socket to SLCM, checked SLCM connectors, reseated, etc - everything good except voltage to right brake light contact is only 7.5 or so volts when brake is depressed.

Ideas? Here are pictures of the SLCM and associated tag.

 

I would suggest you may have a partial break in the power line to the light. Continuity check the line from the module to the light and then compare the reading with the working side.

 

Have you got the same model/make of bulbs fitted? I faffed about with this issue and just renewed all the bulbs on both sides and it started working...I did think it was the end of the SLCM. (does your car give a dash warning?)

I kind of got lost in which bulbs I changed as it was booked in for it's yearly MOT test the morning I noticed the rear bulb out - and all lights must work or its a fail - cleaned the contacts, no light, new bulbs both sides no light, cleaned contacts with a solder cleaner brush, swapped lights round, worked - yup, stress engineering
WD40 the loom connector and connector contacts may need a key with a scotty pad.

 

I had the same problem with my 98 XJR... on mine it was a dirty earth connection behind the right hand boot (trunk) carpet, just forward of the radio antenna (8mm bolt)

It also cured the tempremental boot lights.

 

Hi Sean - Yes, I get the dash warning too. New bulbs all around, etc.

Here's the latest: I dove in again yesterday, and connected the right side bulb holder (for lack of a proper term) to the working left hand side. Upon pushing the brake pedal, the brake light came on, but the audio signal from the reverse sensors started beeping, but only intermittently! Strange.

I did try cleaning the SLCM board as others have suggested, but that made no difference. I have found some new replacement components (8 bucks each), so since I am in the electronics production business, it is no big deal to solder some new components to the SLCM board.

It will be a few days before I can get back to it, but I will let you know how I make out.

Thanks to all for the assistance.

 

One light out, other working; upper light works: sounds like a bad SLCM!

Finding the right one on eBay these days is getting tougher; I lucked out a couple of years ago and got a good one right off for about $65.

 

Thanks to all who offered suggestions. It was the SLCM. I replaced the Infineon switch component P/N BTS409L1 (closest to the middle of the board), and my right brake light now works flawlessly. Could not have found it without the great input from this forum! Thanks again for the help.

 

Scott did you take a pic of the part?

 

Hi Sean,
Here is a picture of the SLCM board out of the plastic box/housing:



The component closest to the big Tyco solenoid is for the right (starboard) brake light.


I replaced it with Infineon P/N BTS409L1 and it worked just fine. I actually sourced the component new on eBay for the princely sum of $8.30 (including shipping) if I remember correctly. The ground tab on top and the center lead must be trimmed to match the installed component lead form - just match the old component form.

Final word: Make sure you or the person replacing the component has decent soldering skills as you must both de-solder and remove the bad component then re-solder the new component. The last thing you want to do is lift a pad or trace and turn the board into junk. Remember to clean all flux residues off after soldering as they can be hydroscopic or with time become conductive and cause problems later.

 

Thanks Scott, great info there mate

 

This thread needs to go into the stickies!