Brake lights

[pontiacvince]

When I first got my '71 Suburban back on the road, I made sure all lights worked. Last week, I bought a set of LED taillight bulbs. Taillights worked, signals worked, but no brake lights. I put the regular 1157 bulbs back in and the brake lights still didn't work. Checked the switch and it tests good. Fuse is good.
I'm all out of ideas. Anyone?

[LockDoc]

Originally Posted by pontiacvince

When I first got my '71 Suburban back on the road, I made sure all lights worked. Last week, I bought a set of LED taillight bulbs. Taillights worked, signals worked, but no brake lights. I put the regular 1157 bulbs back in and the brake lights still didn't work. Checked the switch and it tests good. Fuse is good.
I'm all out of ideas. Anyone?

Presuming you checked the fuse and fuse holder. Sometimes the fuse holder gets corroded or rusted. Test both sides of the fuse with a meter or test light first.

If that tests OK try removing the bulbs and check the contacts with a meter or test light. That will let you know if the contacts in the socket have power or not. You will have to have someone hold the brake pedal down. If the contacts don't have power unplug the connector in the rear, at the rear cross member. No power there check the connector at the firewall.

LockDoc

[dmjlambert]

Also the brake signal first goes through the turn signal switch before it makes its way to the back of the truck.

Use a test light at the steering column connector, which is the curved connector under the dash. Connect the clip of the test light to a good clean ground place, and the pointed probe can go into the back of the connector where the wire goes in, and contact the metal terminals.
You can see if the brake signal that goes into the turn signal switch on the white wire comes out of the turn signal switch on the yellow wire for rear left brake light and green wire for right rear brake light.

Turn signal switch connector wire colors (dash wiring harness side):
white = from brake switch, has voltage if brake pressed
yellow = to left rear light, has constant voltage if brake pressed and if turn signal not in turning left position. has voltage flashing on and off if turn signal switch in turning left position.
green = to right rear light, has constant voltage if brake pressed and if turn signal not in turning right position. has voltage flashing on and off if turn signal switch in turning right position.
light blue = to left front turn signal light
dark blue = to right front turn signal light
purple = from turn flasher, has voltage flashing on and off if turn signal switch in turning right or left position.
brown = from hazard flasher
black = horn, horn button will ground this wire and cause horn relay to turn on

[pontiacvince]

Thanks guys! I would have played with it more today, but the rain drove me inside. We'll see tomorrow.

[pontiacvince]

Well, it was the white wire that pulled out of the plug. When I bought the aftermarket tilt column, I took off the flat plug and adapted the wires to the factory curved one. The white wire pulled out slightly killing the brake lights. Works fine now even after putting the LED bulbs back in Thanks, guys!!!

[LockDoc]

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Good deal, glad you got it sorted out....

LockDoc