C3 Brake Indicator Lignt
Thread Starter
Cruising
Joined: Jul 2011
Posts: 11
Likes: 0
C3 Brake Indicator Lignt
I have owned my 1969 C3 for 4 years and the brake indicator lilght worked without issue until recently. How can I pinpoint if the issue is with the switch located by the emergency brake mechanism or if the light itself is burned out. I removed the cover revealing the switch, started the car and activated/deactivated the switch manually with no response from the brake indicator light. I drove the car today approx 60 miles with no braking issues.
Melting Slicks
Joined: Dec 2000
Posts: 3,363
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From: Lansdale 19446 PA
2024 C3 of the Year Finalist- Unmodified
St. Jude Donor '10-'11, '15, '19
One more location to add - the switch on the brake proportioning valve. Mine is bad and brake light stays on all the time.
Drifting
Joined: Oct 2010
Posts: 1,972
Likes: 6
From: Chester Virginia
not sure on your year about how the brake proportioning valve indicator works but as I understand it on my 76 there is a metal pin below the connection to the middle top of the valve/switch. When the valve body inside moves forward or back more than a certain amount gravity allows that pin to fall and when it does it completes ground and then the signal goes to the brake warning light signalling you have a pressure problem of some type in your brake system. So, I would think if you just unplug the wire connection to the top of your proportioning valve on mine the light goes out....for a short term fix. However, even if the valve is tempermental I have found that the darned thing does give you early warning on brake problems so I'm not sure I'd ignore it. No expert but that's the only explanation I found on the forum and can't find a diagram showing the internal parts of the valve but it does make some sense if it's accurate. Just be sure your light isn't telling you that you have leaking brakes or some other brake pressure related problem.
L.P.
L.P.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I have owned my 1969 C3 for 4 years and the brake indicator lilght worked without issue until recently. How can I pinpoint if the issue is with the switch located by the emergency brake mechanism or if the light itself is burned out. I removed the cover revealing the switch, started the car and activated/deactivated the switch manually with no response from the brake indicator light. I drove the car today approx 60 miles with no braking issues.
If your fuel and temp gauges are working then the fuse to the brake light is good.
Try going out to the engine compartment,remove the tan wire from the brake pressure safety switch and grounding it,key in the on position.
If it doesn't light chances are the bulb is burned out.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
I'm gathering from your post that the light is NOT coming on.
If your fuel and temp gauges are working then the fuse to the brake light is good.
Try going out to the engine compartment,remove the tan wire from the brake pressure safety switch and grounding it,key in the on position.
If it doesn't light chances are the bulb is burned out.
If your fuel and temp gauges are working then the fuse to the brake light is good.
Try going out to the engine compartment,remove the tan wire from the brake pressure safety switch and grounding it,key in the on position.
If it doesn't light chances are the bulb is burned out.
Also, malfunctioning switch in the valve will not stop the lamp from illuminating with the parking brake handle switch.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
Yes, but his question is "What is defective...the bulb or the E-brake switch?" To answer that, he needs to cause the bulb to turn on (if it will) as per Roger's suggestion. If that test doesn't light the bulb, it is burned out.
Thread Starter
Cruising
Joined: Jul 2011
Posts: 11
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I located the tan wire on the brake pressure safety switch. Please verify the tan wire is located between the two brake lines which run from the brake fluid reservoir. I pulled on the tan wire (it has a small rubber boot), but it did not dislodge and I was afraid to apply to much pressure on an old wire connection. Is it a threaded connection or should it just pull off?
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
That's the correct wire. Its a pull off, squeeze around the boot and try to soften it a little and twist a little while pulling. It has a groove and lip design to keep dirt and moisture out.
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Race Director
Joined: Jul 2001
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Agreed, I simply thought the post was taking a side track by suggesting that the valve switch could be the cause of it NOT turning on.
