No Brake lights and shifter lock?

CHIEFFALLINGSTARR

MEMBER
1999 CHEVROLET SUBURBAN
5.7L
V8
2WD
AUTOMATIC
220,000 MILES

My transmission won't shift into park. I've replaced the brake switch controller out. Taillights work turns on and off, hazards work, I've never messed with the hacked-up trailer light harness, and I believe it's finally give out and caused a sleuth of problems. The white signal wire coming out of the harness next to blue and orange thick wires and the plug connector for the brake light harness. They tapped a trailer light harness into Pin B and Pin D. My confusion is the white signal wire, and it having nowhere to go. It was wrapped around a nut next to the frame rail. When it's connected there, I blow my stop hazard fuse and loose door chime and hazards but continue to have working taillights and blinkers. The transmission is stuck in park because there's no signal getting to the lights and I guess signaling the computer to stay in park.

Thursday, June 5th, 2025 AT 11:11 AM

1 Reply

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Hi,

Power to the park release comes from the brake light switch. It's a white wire that then goes to the turn signal/hazard switch. If you connect that white wire to ground, it will cause the fuse to fail. That leads to the aforementioned switch.

I attached the wiring schematic below for you to review. I highlighted the brake light power supply so you can follow. Again, the brake lamp ground is done from the light sockets. As far as the schematic, I had to cut it in half to make it readable, but I did overlap the two so you can follow from one to the next.

Let me know if this helps answer your question or if you have additional ones.

Take care,

Joe

See pics below.

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