High Center Mounted Break Light

06-21-2004, 04:04 PM
I need help in locating the "High Center Mounted Break Light Relay"!!!
My high center break light doesn't work! OM says to check the fuses and relay. GM doesn't know where the relay is located. Fuses are ok and regular break lights work. I have checked the break light/pc board assy and all appears to be ok. No voltage going to it though! Some dealers state that there is no relay although GM gave me a part number.
Please help..........Regards, Lyle

06-21-2004, 11:57 PM
are u sure that is is all that stuff or do u have a bulb that is burned out

06-22-2004, 03:58 PM
There is no bulb, the lamp assembly consits of a printed circuit board and several led's mounted to it with a diode and several resistors.
As I stated, I have checked it and it seems to be ok. There is no voltage going to it when the breaks are applied. This vehicle was purchased new by me and never in an acident. None of the wireing has been messed with. I don't have a wiring diagram but something has failed between the break lamp switch and the lamp assembly. Owners manual states that there is a relay which is what I'm trying to locate to attempt to narrow the search.
Thanks for your reply.

06-25-2004, 06:14 AM
Don't check for voltage at the board, check it at the connector that it plugs in to.

The connector is tucked under the headliner right at the back of the truck. You'll have ot remove a couple pieces of molding, and carefully pull the liner down, the plug should be right there below the left side of the 3rd brake light.

Water has been known to get down in there and corrode those terminals at that connector.

Check there first and let us know what you find.

06-25-2004, 10:59 AM
Thank you for the reply. I'll check that out and get back to you.

06-30-2004, 10:54 AM
Thank you GMTECH, I found the connector right where you said it would be. I had voltage from the vehicle. I removed the light assembly and determined that there was an open circuit from the lamp assembly to it's connector. A broken wire at the grommet where the wiring penetrates the skin of the vehicle. Replaced the wiring and all is well. Thank you very much for the help, you saved me $235 which is what the dealer wanted to repair it!

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