Brake light not working

[cccoltsicehockey]

So my 2002 brake lamp out light came on yesterday when I took the car last night. This is the first time it has ever come on. The rear running lights work but the drivers side does not light up when the brake pedal is pressed. The passenger side brake light and spoiler light work fine so I imagine the fuse is fine. I have swapped bulbs from both sides and the drivers bulbs work just fine in the passenger side and putting the passenger side bulbs in the drivers side doesn't fix the issue. I have used sandpaper to lightly clean out the driver side connectors but that doesn't seem to fix the problem either. I am leaning towards it being a wiring issue since it affects both bulbs on the drivers side. Can any help me with which way the wiring runs so I am not just blindly tearing the car apart to try and trace it or if anyone has any other suggestions that would be appreciated. I don't mind the light on as much as I hate driving around with a brake light not working.

 

[Old Guy]

Open the trunk lid and remove the lining to expose the back of the taillights and the wiring harness. As I recall, the wiring harness runs from the left side to the right side so if the right side is working, the problem is likely confined to the wiring associated with the left brake light. Brake light power goes to both right and left side brake lights on the green/white wire. Check to make sure that you have +12v on that wire on the left side when somebody presses on the brake pedal. Chances are you do and if that is the case the brake light failure sensor may have failed (it is mounted close to the taillight). The two brake lights in the lens assembly share a common ground. Check that to make sure it is OK; but, chances are that if the bulbs are good the sensor may have a problem.

A more complete trouble shooting procedure is contained in the 1997+ service manual if you need it.

 

[cccoltsicehockey]

Very much appreciate the detailed break down. I will check the green/white wire for power.

The brake lights do not light on the drivers side so to me that would seem to indicate no power on that wire? Or would the sensor going bad keep the brake lights from lighting up brighter when you press the brake pedal?

 

[Old Guy]

Very much appreciate the detailed break down. I will check the green/white wire for power.

The brake lights do not light on the drivers side so to me that would seem to indicate no power on that wire? Or would the sensor going bad keep the brake lights from lighting up brighter when you press the brake pedal?

There is a separate sensor for the right light and the left light. The sensor (pretty easy to find, its a small rectangular box) is connected in the path from the green /white wire to the brake light filament. If the sensor fails it is entirely possible to completely lose the connection between the green white supply and the bulb filament on that side.

The light bulbs are dual filament bulbs. There is a low power filament for the taillights which is on a completely separate circuit and a high power filament which is on the brake light circuit. That is why you can have the taillights operating; but, failed brake lights.

 

[cccoltsicehockey]

So yesterday morning I took another crack at figuring out the issue. Disconnnected the drivers side light hardness and cleaned the contacts again. This time I remove all the grease from sindie the connection as well. I also opened the connector plate caps on each side of the connector. Not sure what they are actually called. I made sure all the pins were securely seated as well as probed the connects to try and tell if there were any wire brakes. Does not appear so. Put everything back together then nice and tight and the lights worked again. Weather was beautiful outside for this time a year with temps in the 70s so put 60 miles on the car and the problem stayed away so hopefully I have resolved the problem. Thanks again for the help and sharing your knowledge Old Guy.