Driver side brake light dimming

Hi,

Most commonly, that is an indication of a bad/weak ground. Because of the model year, I don't have a clear wiring schematic, but if I recall, the brake light and turn signal use the same element in the rear bulbs. Either it should be an 1157 or a 2057 bulb. One element works for the parking light and the other for the brakes and the signal.

Do the turn signals seem to work properly? Also, what I need you to do is this. With everything off, we need to determine which wire provides a ground path for the brake lights. So, disconnect the connector and check each wire for continuity to ground. We need to confirm that there is ground. Or, you can use a test light and have a helper press the brake pedal while you check which wire supplies power. That will narrow it down for you.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

Once you determine which wire is ground, just as a test, place a jumper wire between it and a known good ground to see if that changes how the light works.

Let me know. Also, check inside the light socket to make sure there is no damage or corrosion.

Take care,

Joe

Okay, I need you to check for power at the brake light switch. It is located under the dash on the top of the brake pedal.

Also, I need to know if you have cruise control and I realize it's a w100, but my manual is showing a truck and Ramcharger under the w100.

I attached a pic below of the location of the switch. Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

Also, if you can, check for power at the tail lamp sockets. You will need a helper to press the brake pedal.

Let me know.

Joe