When I had my tires balanced today, I noticed my back-up light on the driver side did not illuminate when they backed out. Then this evening I noticed when I unlock the car the lower brake light does not flash on that side either. I have confirmed that the trun signal and brake light still function correctly. I am going to pull out the lamp assembly this weekend to replace the back-up bulb, but I am stumped as to why the brake light does not flash when unlocking the car if it works correctly when applying the brakes. Any ideas? Thanks .....

 

IIRC they are dual filament bulbs. One of the filaments are bad. Replace the bulb.

 

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