New brake master cylinder to old wiring (1 Viewer)

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Is it possible to connect this brake master cylinder wiring into my old wiring harness and back to my red brake warning light?

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Simple answer is yes. How you do it will depend on if you are willing to cut into old wiring or want to use connectors and wire to bridge the systems. What year are you dealing with and is the wiring still intact?
 
This may have the information that you are looking for.
 
Simple answer is yes. How you do it will depend on if you are willing to cut into old wiring or want to use connectors and wire to bridge the systems. What year are you dealing with and is the wiring still intact?
It's an 11/71 the wiring is fine, I'm pretty sure the original connectors fell off though. And I can't seem to find any diagram that shows the correct color. I have 2 loose blue/red wires but the diagram shows green/white, which makes sense because the parking brake and brake light on the dash is green/white. And my original master cylinder only used 1 wire but this new one uses the black and white. Should I ground one?
 
This may have the information that you are looking for.
I was just going to snip the connector and put on these factory style bullet connectors I have a bunch of...

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The early brake light works like this

The two pressure switches are normally closed with no pressure on them. They monitor pressure in the MC. They provide a ground to the brake warning light via the GW wire. The light is held off by the brake pedal switch (open with no foot on brake.) So when you mash the brake pedal, the brake pedal switch closes (turning on brake lights), and turning on red brake warning light if there isn't sufficient pressure in the MC.

The brake pedal switch has two contacts in it, one side feeds the brake lights, the other feeds the brake warning light.
 
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I have the later cap in my 73. You could wire the GW wire that went to the old pressure switches to the new cap, provide a ground to the other cap wire, then jumper the brake pedal switch (the side that feeds the warning light). So when you get a low level, the cap switch closes and grounds the warning light, turning it on. Use at your own risk.
 

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