Brake line electric male blade connector

[K10-Kansas]

Hi! I have a electric blade connector running from a component that looks to be the intermediary between left and right brake lines and I'm not sure what should be connected to this blade. This is mounted to the frame under the radiator. The lines from my master cylinder run down to this intermediary. Thanks for the help.

[Richard]

That is the proportioning valve. On a stock 71 it would be right next to the master reservoir. The wire would connect to the "Brake" trouble light in the instrument cluster. Provides a ground to turn light on typically if fluid/pressure loss in the front or rear brake system.

[K10-Kansas]

Originally Posted by Richard

That is the proportioning valve. On a stock 71 it would be right next to the master reservoir. The wire would connect to the "Brake" trouble light in the instrument cluster. Provides a ground to turn light on typically if fluid/pressure loss in the front or rear brake system.

Oh thanks. I haven't put in my gauge cluster yet so I haven't seen the brake light on the dash yet. My new wiring harness doesn't have a wire to run to the proportioning valve. I guess I better call American Auto Wire tomorrow and ask about that.

[72SB]

IIRC the wire color to the brake proportioning valve sensor is brown

[leftybass209]

Originally Posted by K10-Kansas

Oh thanks. I haven't put in my gauge cluster yet so I haven't seen the brake light on the dash yet. My new wiring harness doesn't have a wire to run to the proportioning valve. I guess I better call American Auto Wire tomorrow and ask about that.

Is the wiring harness you bought a newer DIY that you build, or is it a prefabbed unit that's routed like original?

the wire for the brake prop valve runs out of the left side of the distribution block, upper left hand side. Should be tan, but i've also seen blue.

[LockDoc]

Originally Posted by K10-Kansas

Oh thanks. I haven't put in my gauge cluster yet so I haven't seen the brake light on the dash yet. My new wiring harness doesn't have a wire to run to the proportioning valve. I guess I better call American Auto Wire tomorrow and ask about that.

Here is a picture of where the brake warning light is in your cluster.

There is probably a wire there for the "proportioning" or "combination" valve. It should be a Tan colored wire and it should be labeled. The wire may be too short because it would be for the brake booster mounted valve. If that is the case you would have to lengthen the wire so it would reach the lower frame mounted valve.....

LockDoc

[K10-Kansas]

Originally Posted by LockDoc

Here is a picture of where the brake warning light is in your cluster.

There is probably a wire there for the "proportioning" or "combination" valve. It should be a Tan colored wire and it should be labeled. The wire may be too short because it would be for the brake booster mounted valve. If that is the case you would have to lengthen the wire so it would reach the lower frame mounted valve.....

LockDoc

Thanks, I downloaded the wiring diagram from American Auto Wire and searched the word brake and found it. It was an add on for the bulkhead so I added it on and connected it up. Thanks. I guess I should crawl all over this truck and look for other random non-connected things.

[LockDoc]

Originally Posted by K10-Kansas

Thanks, I downloaded the wiring diagram from American Auto Wire and searched the word brake and found it. It was an add on for the bulkhead so I added it on and connected it up. Thanks. I guess I should crawl all over this truck and look for other random non-connected things.

No problem.

LockDoc

[dmjlambert]

Originally Posted by K10-Kansas

Thanks, I downloaded the wiring diagram from American Auto Wire and searched the word brake and found it. It was an add on for the bulkhead so I added it on and connected it up. Thanks. I guess I should crawl all over this truck and look for other random non-connected things.

You can test your brake warning circuit by bleeding the front brake while ignition key is in the on position. When you press the brake pedal and some fluid comes out of the caliper bleeder, the light should come on. Close the bleeder and repeat test with rear brake bleeder open. Reset the valve and light if you need to between tests or after tests, by pressing on the brake firmly with bleeders closed. The 71 and 72 service manuals have this procedure for testing the warning light switch, I've given a much abbreviated version. The manuals:
https://67-72chevytrucks.com/vboard/...d.php?t=558016

If you should need work on that combination valve, I have sent mine to White Post Restorations and had good results from them. I recommend don't change it out with some Chinese junk new replacement proportioning valve.
If you ever desire to move that valve to be up by the master cylinder, the metal bracket that mounts it there is reproduced.

[K10-Kansas]

Originally Posted by dmjlambert

You can test your brake warning circuit by bleeding the front brake while ignition key is in the on position. When you press the brake pedal and some fluid comes out of the caliper bleeder, the light should come on. Close the bleeder and repeat test with rear brake bleeder open. Reset the valve and light if you need to between tests or after tests, by pressing on the brake firmly with bleeders closed. The 71 and 72 service manuals have this procedure for testing the warning light switch, I've given a much abbreviated version. The manuals:
https://67-72chevytrucks.com/vboard/...d.php?t=558016

If you should need work on that combination valve, I have sent mine to White Post Restorations and had good results from them. I recommend don't change it out with some Chinese junk new replacement proportioning valve.
If you ever desire to move that valve to be up by the master cylinder, the metal bracket that mounts it there is reproduced.

Perfect, thanks. I'll test it to make sure it's working right.