3rd brake light

[MYT HI]

so the cab we have is a 94 (which has the 3rd brake light) and all the wiring in the entire truck except for that is from a 90. Well the 90 didn't have a 3rd brake light. does anyone know how I could wire that in?

 

[eric.s.t]

I would probably. Splice in at the brake pedal, or at the wiring that goes to the rear tail lights.

 

[glfirefighter144]

I would probably. Splice in at the brake pedal, or at the wiring that goes to the rear tail lights.

i'm with him, just find a place that won't get mixed with the blinkers

 

[SCOTTYINWV]

That should be fairly easy. Get a test light and find which is the brake light wire vampire clips would work to tap it in

 

[35olds]

I've got an 1988 and am having the same trouble.Everything works,but for the life of me,I can't find 12 volts coming from switch .My tester works.Any help?
Thanks

 

[FastOrange]

Third brake light should only light up when brakes are applied, if u splice in at taillight you might get them on with park lights too.

Not sure if that's legal or not, I can't see why it wouldn't be.

 

[IOWNJUNK]

I've got an 1988 and am having the same trouble.Everything works,but for the life of me,I can't find 12 volts coming from switch .My tester works.Any help?
Thanks

Are you testing for voltage with brakes applied?

 

[35olds]

YES,I've done complete wiring on older cars.The old ones are really easy to add anthing elecric.I,with blocks,keep the brake pedal depressed.I have break lights,everything works.I test one wire at a time.I get nothing.I'm beginning to think,that two wires from brake switch are hot at the same time.ANYBODY ,ANYBODY,HELP!! Thanks,35olds

 

[35olds]

Also,along frame rail under the door area,I've checked here as well,nothing.Now ,also there is,in the wire loom,is what looks like a plastic tube.I do not know what is in that tube.I've found 3 wires here,but none are hot with brake pedal depressed.