Why won’t that brake light work?

March 1, 2011 | By Richard Prince


The left side brake light works properly on my 1964 Chevy II, but the right side does not work. I have replaced the bulb on the right side, but to no avail. Both signal lights (right and left) work properly. Any suggestions on how to troubleshoot this problem? Can you recommend a source for a simplified wiring diagram, like the lighting system only for my 1964 Chevy II 4-door sedan?


You can find comprehensive wiring diagrams in the Chevrolet factory service manual for your car or you can buy the wiring diagrams from most of the major restoration parts suppliers.

The brake lights in your car are a fairly simple circuit. You’ve eliminated the obvious causes of failure, including a bad bulb, and the fact that the signal light works on the right side indicates that the ground to the lamp housing is good. The problem, therefore, most likely lies in the turn signal switch.

The brake light circuit goes through the turn signal switch, which is configured so that the signal function overrides the brake light when both are activated. In most vehicles both the brake light and turn signal use the same element in the same bulb so in order for the signal to flash when the brakes are applied there has to be a mechanism in the signal switch for interrupting the brake lamp circuit. Your problem likely lies in either the signal switch itself or in the wiring that comes out of it. If it’s in the wiring, the connection where the signal harness plugs into the body harness is a probable trouble spot.