need brake light help

[tnblazerk5]

ok my brake lights quit last nite but i have tail and blinker lights ,the bulbs are good and the fuse is good. how does the brake switch work power wise, does it ground or what ?

[68w/sbc406]

i imagine it controls power. keeps power from ggoing to the brake element. pull the wires off the switch and touch them together. if your brake lights come on then you know its the switch

[tnblazerk5]

Originally Posted by 68w/sbc406

i imagine it controls power. keeps power from ggoing to the brake element. pull the wires off the switch and touch them together. if your brake lights come on then you know its the switch

i did that and nothing

[kwmech]

Power to the orange wire at the switch comes from the fuse block, white wire goes from the switch up the steering column and back down the yellow and green turn sig wires and then to the rear bulbs. So ---if your turn sigs work, and the fuse is good, then you are looking at a bad switch or a connection between the switch and the column connector.

[68w/sbc406]

then i wouldnt think that it is the brake switch then. hmmm.......did they just stop working or did you work on something and now they dont work? i painted my light housings once a while ago, then when i put them back in i was thinking to myself, 'wow that really brightened it up' but then i had no brake lights. what had happened was the connections on both tail lights had pushed out and turned so that the tail light one was on the brake light, and the brake light was on the tail light. so when i stepped on the brakes i couldnt see the other filiment lighting up. other than that i would say doubble check the fuses and bulbs, maybe the tail light wires that run down the frame, and the plug at the rear most crossmember. has the harness been hacked into for trailer lights? maybe a concetion went bad??? that all my ideas

[tnblazerk5]

i just noticed them not workin last nite (local law pulled me over ) i just recently put a van tilt in and took the clutch petel out (now auto trans) so i have been doin a bunch of work onder the dash i will have to go out there now and look around alittle more (now that its daylight lol)

[68w/sbc406]

then it might be in the column like kwmeck said

[tnblazerk5]

ok i went out there with my testlight and have power at the orange wire but with the brake petel pushed didnt have power to the white wire so i got to get a brake light switch

[pjmoreland]

If you shorted the orange and white wires together like 68W/sbc406 suggested, and your lights didn't come on, then you have a problem somewhere other than with your switch. The switch could be bad too, but there is something else besides the switch that isn't working.

[Sillyoldman]

Not likely the problem, but a new bed wire harness is about $75.00. It was a painless install. I was amazed anything worked after seeing the old one.

[pjmoreland]

The orange wire provides 12V to the brake switch. If you are pressing your brakes, and the brake switch is functioning, the 12V provided by the orange wire should pass through the switch and into the white wire coming out of the switch connector. The white wire then connects to the curved connector for the steering column. If your turn signal switch is in the neutral position, then the white wire should be connected to the dark green wire and the yellow wire that come out of the steering column connector (the dark green wire is for the right brake light, and the yellow wire is for the left brake light). The dark green and yellow wires go from the steering column to the connector on the firewall that is just to the left of the heater box, and then back to the brake lights along the left rail of the chassis.

With the brake pedal pressed down, or with the brake switch connector removed and the pins shorted together, you should be able to measure 12 volts first at the orange wire on the brake switch connector, then at the white wire on the brake switch connector, then on the white wire at the steering column curved connector, then at the dark green and the yellow wires at the steering column curved connector, then on the dark green and the yellow wires at the firewall connector, then on the dark green and yellow wires at the connector at the rear end of the chassis (behind the bumper), and finally inside the light bulb sockets.

[tnblazerk5]

it was the switch and i went and got a new one and they work now

thanks everybody

[tnblazerk5]

Originally Posted by pjmoreland

The orange wire provides 12V to the brake switch. If you are pressing your brakes, and the brake switch is functioning, the 12V provided by the orange wire should pass through the switch and into the white wire coming out of the switch connector. The white wire then connects to the curved connector for the steering column. If your turn signal switch is in the neutral position, then the white wire should be connected to the dark green wire and the yellow wire that come out of the steering column connector (the dark green wire is for the right brake light, and the yellow wire is for the left brake light). The dark green and yellow wires go from the steering column to the connector on the firewall that is just to the left of the heater box, and then back to the brake lights along the left rail of the chassis.

With the brake pedal pressed down, or with the brake switch connector removed and the pins shorted together, you should be able to measure 12 volts first at the orange wire on the brake switch connector, then at the white wire on the brake switch connector, then on the white wire at the steering column curved connector, then at the dark green and the yellow wires at the steering column curved connector, then on the dark green and the yellow wires at the firewall connector, then on the dark green and yellow wires at the connector at the rear end of the chassis (behind the bumper), and finally inside the light bulb sockets.

good write up there pjmoreland

[pjmoreland]

Glad to hear you got it figured out. It doesn't matter now, but it just occurred to me that the problem had to be either with the brake switch or with the turn signal switch because your blinkers work, and the blinkers use the same wires as the brake lights from the turn signal switch back to the bulbs.