center brake light

1987 CHEVROLET MONTE CARLO
150,000 MILES • 3.2L • V8 • 2WD • AUTOMATIC
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RMCARA
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I have the SS model.
My center brake light does not work. There is power when the brake is pressed. I checked the socket offline and the bulb lights when power is applied. When I install a bulb into the socket the voltage goes to zero. The lower break lights work as they should.
Jul 8, 2017 at 7:23 AM
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STRAILER
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Hello,

It is just a straight wiring coming from the brake light switch to the top mounted brake light. Here is a wiring diagram (below) and a guide to help you do some testing and get the problem fixed.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Please run some tests and get back to us we are interested to see what it is.

Cheers, Ken
Jul 10, 2017 at 11:02 AM
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RMCARA
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Thank you, I'm going to try running a separate ground wire. I'll reply in a couple of days.
Jul 11, 2017 at 2:16 AM
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STRAILER
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Please let us know what happens.

Cheers, Ken
Jul 11, 2017 at 3:41 PM
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RMCARA
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Problem solved. Using a multi meter to measure voltage can give misleading readings because the meter does NOT apply a load to the circuit. When I used a test light to measure the voltage at the light socket, I did not have any power at the light. A friend of mine who is an electrician told me the proper way to measure voltage is with a test light because it applies a load to the circuit. Using the wiring diagram from Ken, my friend noticed that the light switch has two contacts, one for normal brake lights and one for the center light. He snapped the switch several times and contact was made to the center light. All is well that ends well. Light now functioning correctly. Thanks for the help.
Jul 14, 2017 at 2:33 AM
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STRAILER
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Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help

Cheers, Ken
Jul 14, 2017 at 9:34 AM