Wierd electrical issue, '98 suburban

[moneypit_K5]

Just picked up a 6.5TD 2500 burb.

whenever the brake pedal is pressed, the turn signal fuse blows.

if the pedal is not pressed, turn signals work fine except,
I have no brake light or turn signal on the passenger side rear. there is no power getting through.

I have unplugged the wiring harness at the outside of the firewall that runs all the rear tails/turns/brakes etc, thereby placing the issue under the dash somewhere.

I preemptively installed a new turn signal switch after much fruitless diagnostic, because my cruise is also out and is in the same switch.

didnt change anything.


Im fresh out of ideas. Anybody have some advice, or possibly some model specific wiring schematics for the turn/brake circuits?

 

[dhcomp]

Just picked up a 6.5TD 2500 burb.

whenever the brake pedal is pressed, the turn signal fuse blows.

if the pedal is not pressed, turn signals work fine except,
I have no brake light or turn signal on the passenger side rear. there is no power getting through.

I have unplugged the wiring harness at the outside of the firewall that runs all the rear tails/turns/brakes etc, thereby placing the issue under the dash somewhere.

I preemptively installed a new turn signal switch after much fruitless diagnostic, because my cruise is also out and is in the same switch.

didnt change anything.


Im fresh out of ideas. Anybody have some advice, or possibly some model specific wiring schematics for the turn/brake circuits?

There is a control board/circuit for the brake/tail/turn signals in that truck. I don't know it in detail, as i didnt' replace it, but in our 96 it shorted and burned out. What did the turn signal stalk plug into? I'd be looking at that.

Our trailer harness had water in it, and would cause the turn signal fuse to blow everytime we towed a boat. Eventually, it cooked the control board.

 

[moneypit_K5]

so you are saying there is separate control for the turns other than the giant multi function switch?

 

[dhcomp]

so you are saying there is separate control for the turns other than the giant multi function switch?

I think so....but then again, i'm not positive.

I just remember them replacing some control module , that sounded separate than the stalk.