Mechanics

MY BRAKE LIGHTS DO NOT WORK WITH KEY ON, BUT DO WITH THE KEY OFF. MY BRAKE SWITCH WORKS AND HAS POWER BUT NOT THE MULTIFUNCTION SWITCH

1994 Chevrolet Silverado

I have traced it through the dash but it dissappears behind the gauges. I dont know where the brake switch and the multi switch intersect
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Zdaily
October 10, 2012.



Do the brake lights work with the key off?

Roy
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ASEMaster6371
Oct 10, 2012.
Yes they do, but ive been messing with so much that just now they do not


Tiny
Zdaily
Oct 10, 2012.
Except for the high mount brake light, the other stop lights are linked to the hazard/turn signal switch and that shuld be the component you should be looking at for the fault.

Refer to the schematics.


KHLow2008
Oct 10, 2012.
There is no power going to the signal switch. This is where I am getting stumped


Tiny
Zdaily
Oct 10, 2012.
I have a new switch and that did not change anything. There is no power to the switch in general


Tiny
Zdaily
Oct 10, 2012.
The yellow wire from the brake switch has power. But the white wire that connects to the signal switch has power for a seconds and then dims to nothing. This is with the key on. Why would this happen?


Tiny
Zdaily
Oct 10, 2012.
When power to White wire fades, check Yellow wire again. If power is available, the brake switch is the one causing the problem.


KHLow2008
Oct 10, 2012.
So I just installed a new brake switch and that did not fix my problem. And the grounds in the back near the lights are all good. I am losing power in between the signal switch, and the brake switch. Is the wire grounded somewhere in between that might have rattled lose?


Tiny
Zdaily
Oct 11, 2012.
The yellow wire from the brake switch, is spliced to 4 other yellow wires, from there two wires run up and behind the dash. Another runs to the relays that still has power and the other runs to a junction that is connected to 5 other wires that also stays hot. The 2 wires that run up and behind my dash, I don't know where they lead but a white wire comes from there back down and to the signal switch. What happens in between?


Tiny
Zdaily
Oct 11, 2012.
You did not specify the exact model of your vehicle resulting in me posting the wrong schematics previously. Here are the correct schematics.

The two wires going up to dash should be for the the cruise control and auxiliary usage.

Inbetween is the center high mount stoplight relay, which is located at right hand side of cowl, in engine compartment. The White wire to signal switch must have battery voltage when brake switch is operated. If no voltage is present you need to check the relay.


KHLow2008
Oct 11, 2012.
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