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I just noticed my parking brake dash light is staying on. I thought the switch under the console might be stuck, but it's moving like it should. I'm not that good with a multimeter but I do have one. Can anyone tell me how to go about finding the problem or testing the switch? My brakes are all in good shape and fluid reservoir is full.
There is a switch on the brake proportional valve located in the brake lines from the master cylinder. It will turn on the brake light if there is a problem. I am only guessing as you don’t indicate what year Corvette you have. You will see a wire going to the valve. Google brake proportion valve to learn how to diagnose the problem.
There is a switch on the brake proportional valve located in the brake lines from the master cylinder. It will turn on the brake light if there is a problem. I am only guessing as you don’t indicate what year Corvette you have. You will see a wire going to the valve. Google brake proportion valve to learn how to diagnose the problem.
Thank you for the reply. I have a 1979 Corvette. Don't think it has a wire located on the on the brake proportioning valve. I tried a multimeter with the red prong on the wire going to the switch and the black to a ground, but not getting any reading? Haven't had a chance to check out the proportioning valve, but after checking out Youtube, I think you're right! I'm going to take a look in the morning. Thanks.
Last edited by sircharles007; Apr 26, 2022 at 05:16 AM.
The wire leading to the combination valve should be hot (+12V) when IGN is ON. The switch inside acts to ground the brake light when it detects a brake failure, and pushes the plunger to one side or the other. Check for continuity from the spade connector on the switch to ground.
FWIW, there are three ways that light is lit, all of them are switched grounds.
During cranking, grounded by the ignition switch, to test the bulb
The normally closed switch under the parking brake lever (when the lever is at rest, it pushes the switch plunger, and opens the contact).
The combination valve switch under the hood
If you disconnect the end of the wire from the offending switch, the light should go out, if the problem is the switch. The path to ground may be further upstream in the wire leading to one of the three switches.
Did you mean to post this reply in this thread, and not in the dreaded related thread?
Originally Posted by sircharles007
Yes. The light that comes on on the the dash when the parking brake is applied. I did lose some brake fluid when I was messing around with the rear caliper and never bled the brakes. I'm going to check the proportioning valve in the morning. Pretty sure that's where the problem lies, Thanks.
If so, it sounds like you're all set! Good luck with the bleeding.
Success!!! I had no idea that the proportioning valve could cause the brake light on the dash to come on! After checking Youtube I was able to remove switch on the valve and use a jewellers screwdriver to reposition the valve back to where it should be. And BAM! No more dash light. Thanks so much for the heads up!
Success!!! I had no idea that the proportioning valve could cause the brake light on the dash to come on! After checking Youtube I was able to remove switch on the valve and use a jewellers screwdriver to reposition the valve back to where it should be. And BAM! No more dash light. Thanks so much for the heads up!
That's good news! Be sure to fix the actual brake issue, too, or the light will return as soon as you brake hard.
There are lots of bleeding threads on the Forum. I use a Motive 105 power bleeder, and a big clamp. Motive also makes nice bleeder bottles.
Parking Brake Light
