2002 Pontiac Grand Prix stop light circuit

[rod3]

Does anyone have a wiring diagram for a 2002 Pontiac Grand Prix that would include the stop light circuit?

[BNaylor]

Welcome to AF.

What specific issue are you having with the brake lights?

[Mickey#1]

IIRC - power goes from the stop light switch through the turn signal switch then to the bulbs. PM me with an email address if you want a wiring diagram.

[rod3]

Originally Posted by BNaylor

Welcome to AF.

What specific issue are you having with the brake lights?

The rear window stop light works. Fender mount stop lights do not. Tail lights and turn signals work. Stop light fuse is OK.
Thanks, Rod

[Mickey#1]

Wiring diagram sent.

The brake lights & turn signals use the same wiring from the turn signal switch (AKA Multi-Function switch) to the bulbs. Since the turn signals work you can rule out any problems with that portion of the wiring.

Since the center stop light works you can rule out a problem with the fuse & stop lamp switch.

Now that i'm looking at the diagram, I see the power also goes through the Hazard portion of the Multi-Function switch. This may be where the problem is because the right & left brake lights each have their own set of contacts in the turn signal portion of the Multi-Function switch. Try turning the Hazard lights on & off a few times & then recheck the brake lights.

Most likely the Multi-Function switch is bad. The only other thing is a break in white wire that goes from the stop lamp switch to terminal A1 of the Multi-Function switch. You can test for 12 volts at that wire while pressing the brake pedal.

[tblake]

I agree, the multifunction switch is a common failure point of numerous GM's causing the symptoms you describe.

Just for diagnosis, try wiggling the switch around and flicking on your high beams and see if you have brake lights.