Instrument panel light question

[Jgonick]

Can you get a picture of the switch on the brake pedal

it will be a tan/black wire on a 74


this is the switch on my 85 (i had it unplugged at the time) - not 100% sure if it is the same switch on older square bodies.

 

[75gmck25]

My ‘75 did not have a light to tell you the parking brake was on, but it does have a wire going to the proportioning valve, which turns on the light in the dash if there is a brake line failure. This light works by grounding the wire to turn on the dash light.

Newer trucks did have parking brake light switch (like shown above), so I looked up the part number and bought one. Took a little time to figure out how it mounted, but it bolted right onto my brake pedal mechanism.

I connected one side of the switch by splicing it into the existing wire going to the dash light (tan/black?), and for the other side I ran a wire to ground. It works great, and (ignition on) turns on the brake warning light once the pedal is down about two clicks.

 

[Chris64]

Updates:
1) The front bulb arrived. That seemed to solve the problem of the blinker light coming on with the headlight.
2) The right dash blinker still doesn't work.
3) The right front blinker also doesn't work on either the front or marker light. The left side toggles between the side and the front marker which is pretty slick.
4) The rear right blinker works fine (blinks a little slow because not enough current draw).
4) There's single ground line going from the parking brake bracket to the large dash harness and it looks fine.

So I have more wire debugging in my future. At least I have a working left side to compare.

 

[Jgonick]

The right front blinker also doesn't work on either the front or marker light.

So initially it worked but now it's not working at all?

Just confirming you got the correct bulb- it should be a dual filament bulb ( I think 198)

 

[AuroraGirl]

So initially it worked but now it's not working at all?

Just confirming you got the correct bulb- it should be a dual filament bulb ( I think 198)

198 is a single filament

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[Jgonick]

198 is a single filament

1157 - I guessed wrong.

 

[AuroraGirl]

1157 - I guessed wrong.

side marker is what you were thinking its a 194 it only blinks with the turn signal because it gets two 12v hots when the headlights on and turn signal in the front flashes on (so the 194 sidemarker goes out) , then comes back on when the turn signal is off

Then when not headlights on, i believe it blinks with the turn signal because it has a ground and a hot, but i dont remember well enough or care to go check

 

[Chris64]

The light is a 1157 so I believe it's the correct one. The marker light on the side I think is correct. Just because I had it, I put a dash bulb in the side spot planning on changing it but it turns out that bulb is the same as the dash bulb. Weird.

 

[Jgonick]

Purple wire brings power from flasher. Dark Blue takes it to dash indicator and front right.
dark green goes to back right.

LINK to wiring diagrams