Brake Warning Light On The Dash (70 & 71)

Does anyone know what this light is connected to to make it work? It has switched power to it on one wire and the other wire goes through the firewall to? Mine is disconnected. I don't see it in the wiring diagram (or maybe I'm just missing it.)

Is the light's purpose as an indicator for low brake fluid or pressure, or, does it indicate the parking brake is engaged?

 

It's factory. I've seen it on other rigs. See #5 from the FSM.



I would think it would go to a pressure switch or mechanical switch to ground. The power is through the indicator but the wire out of the light is not connected. I tried moving the end of wire in it's radius but can't see anything obvious to connect it to.

 

I don't know for sure, but they were present in the '70s. Typically it warns when there is a pressure imbalance between each side of the dual master cylinder. Should be in the FSM. I don't see it in the '72 TSM, but it's present in the '74 book.

 

I think that might be fixable. My guess would be that they are hooked to the tail light side of the turn Signal switch. That would make them match the tail lights. Maybe they should connect to the front signals instead?

You were looking for something to do....

 

Tim is correct, 75 also.

 

I agree. But don't seem to see where that switch might be . I have a dual reservoir and and it has been replaced.

 

You'd need a junction block for the switch - should be down at the frame. In the '74 and '75 era the Jeeps had a combination valve that housed the switch.

 

Tim nailed it. I had a '74 CJ with the brakes really messed up. I could either get the front brakes or the rear brakes to work, but not both at the same time. It finally came down to a brass junction block mounted on the drivers frame rail below the firewall, downstream from the master cylinder. That brass junction block had a shuttle valve (actually a tilt valve) between the front and rear brake circuits. It was designed to shut off a circuit if that side had a failure, like a ruptured line. There is an white plastic electrical contact that where the shuttle valve acts as a switch, turning on the dash light in event of the failure. The junction block I had was "modified" by someone leaving a part out, so the shuttle just floated.
I ended up pulling a similar brass block off an old AMC Matador and making it fit the CJ5.
-Donny

 

Thanks all. That will give me something to look for.

 

With the above clues I found this.



Connector hooked up.



Grandson woke up and Nana called. Will test soon.

 

Bingo.