Plug that goes into the housing for the rear lights
I’m in the process of installing LED lights for my brake lights. Everything I’ve read you need to put in a voltage regulator to stop the dreaded check rear lights on your dash coming up. I have the lights I have the voltage regulator. But I can’t determine which two leads or the right wires to hook the regulator to. Attached is a picture of the plug can anyone tell me what to colors activates the brake light when you push the pedal. Thank you in advance for any help

 

There is an electric diagram booklet available in the stickies of this X308 section, from there you should be able to determine the color(s).

Or, practically, if you turn the unit around, you see all the leads going to each recessed bulb holder.
For the brake light bulb, there are 2 leads, one for the 5W rear, an other for the 21W brake, both going to the same recess.

Determine on the old bulb which is which by testing on a 12V source.

Then just follow the lead(s) through the labyrinth, you should be able to locate the corresponding pin, then the color going to that pin.

(I did the same for my rear light, when I added the x300 reflector lights, it's easier than writing this down...).

 

Thank. Will do

 

Any more advice on this would be good, I used the Warning Light Canceler below and hooked it to the Red and Blue wires which I believe after tracing back are the ones that power the brake light when the pedal is hit. I also used the LED bulb below but I am still getting the "Check Rear Lights" and the yellow warning light when I hit the brake pedal.

Questions and Thoughts:
1. Is the Red and Blue wires the right wires? Did I trace them back right?
2. Is the pictured Warning Light Canceler the right one? If not, can someone recommend another one that will do the job?
3. Is that the right type of LED brake light bulb?

Once again, any help is appreciated and I welcome any advice.
Dave Mc

 

To all - just to wrap up this post, I have now successfully installed LED Brake Lights on my 2000 Jaguar XJ8 Vanden Plas without the error message on the dash. The key was the Phillips CANBUS error canceler connection on each brake light assembly.

Drivers Side - need to connect the Phillips error canceler to the BLUE (Hot) and Black (Ground) wires
Passenger Side - need to connect the Phillips error canceler to the ORANGE/WHITE (Hot) and Black (Ground) wires.

Then just install the LED brake lights.

No more errors showing at all on the dash - I hope this helps someone in the future as my cars exterior now has 100% LED lights and looks great.