Volvo Owners Club Forum - View Single Post

PVSPete · Jul 15th, 2021, 00:01

XC90 2011 brakelights in main light units not working but high level brakelight is. 2011 model so REM fusebox module is transistorised with no relays to replace. Bulbs / fuses fine. I've replaced the REM with a second hand one and no change. More testing has shown that the REM resets itself and the brake lights do actually work . . . until the sidelights are either switched on or come on with the ignition . . . at which point the REM shuts down the brakelights. So there must be a fault, but where? So I unplugged the main light clusters, one at a time and the tailgate wiring but everytime I activated the sidelight circuit, the brakelights stopped working. My guess is some sort of earthing fault or perhaps damaged wiring, but where? Any thoughts anyone?

Jul 15th, 2021, 00:01	#1
PVSPete Junior Member Last Online: Jan 5th, 2024 15:14 Join Date: Nov 2019 Location: Peterborough	Brake lights not working XC90 2011 brakelights in main light units not working but high level brakelight is. 2011 model so REM fusebox module is transistorised with no relays to replace. Bulbs / fuses fine. I've replaced the REM with a second hand one and no change. More testing has shown that the REM resets itself and the brake lights do actually work . . . until the sidelights are either switched on or come on with the ignition . . . at which point the REM shuts down the brakelights. So there must be a fault, but where? So I unplugged the main light clusters, one at a time and the tailgate wiring but everytime I activated the sidelight circuit, the brakelights stopped working. My guess is some sort of earthing fault or perhaps damaged wiring, but where? Any thoughts anyone?