1996 GMC Jimmy brake lights

Replace the turn/hazard switch your power goes thru there before it gets to the bottom brake lights.

Hello
Thanks for the donation.

I believe the high mount stop lamp is seperate from the rear stop lamps. Check the relay for power located at center rear of engine compartment. You may also want to start with replacing bulbs. Your bulbs are double filament which means that they actually have two lights in it.

Post results and I will follow up..

Thanks for using 2carpros.com!

I have checked for the relays and the only ones on the engine are the air conditioning relays( I am still looking), The bulbs are all lighting.ex. There are two filaments on each bulb, one is above the other, both upper filaments work with the lights on, and when the turn signals are activated, the lower filaments come on. I checked another blazer (of another year) and found that the turn signal overides the breaks.
As for the hazzard switch , does this send power to the brake pedal switch? Is the break pedal switch a simple on/off switch or does it send different amounts of current out. It seems like some current is going out of the break switch in order to run the middle light, maybe not enough power to run the other lights.
sorry about all the questions , just trying to understand how all of this works.
(hazzard switch )>(break switch)=lights ?

No problem at all. That is what we are here for. :)

If all filaments in bulbs are lighting then my suggestion would have to be to replace the brake light switch. You CAN adjust them if you feel this will help.

Brake light switches are mounted on brake pedal arm. When brake pedal is not in use, it depresses the switch's plunger [holding the switch OPEN] shutting off the brake lights. When the pedal is depressed it allows the switch plunger to extend, closing the switch and allowing electrical current to the circuit and the brake lights illuminate.

Switch is mounted by screwing a threaded nipple on the switch into a threaded hole in a mounting bracket. This switch is adjusted by screwing the switch further out or in.


For wire troubleshotting you should check around the trailer connector for a short. Also under the bumper should be a harness that splits off the taillights. Take a circuit tester and check for shorts here as well.

The high mount (third) brake light is not wired through this switch but the two brake lights are. The switch also cancels the brakes for turn signals and hazard lights and it will wear out eventually.

Hope this helps..
Thanks for using 2carpros.com!

Below is the exterior lights EWD -unable to read it give me your email addy.

[email protected]
I have the haynes manual .
your schematic looks a little different but like you said I cant read it.

Its on its way-let me know what's going on

Thankyou for the schematic. tomarrow I plan to try changing the hazzard switch . I took the break switch off and found that there is not any adjustment to it. I have power to the hazzard switch but cannot tell if there is power leaving it.
So I will try a ground on the light to see if maybe it broke somewhere along the way and another switch.
Incidently I have found a wire coming off of the trailer hookup that has power when the breaks are applied, doesnt when they are released. This wire was not hooked up to the plug but was in the harness taped off .
either way I totally apreciate the help that I have recieved and will donate as much as I can when I can. thank you
kevin

I WOULD LIKE TO THANK ALL OF YOU FOR YOUR HELP. IT TURNS OUT THAT THE HAZZARD SWITCH WAS FAULTY. I WAS ABLE TO REPLACE IT WITH A USED SWITCH AND HAVE ALL MY LIGHTS BACK.
I WILL BE USING THIS SITE IN THE FUTURE FOR MY QUESTIONS.
THANKS AGAIN
KEVIN