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Q: Both of the low beams in my 2012 Malibu burned out at the same time. I replaced them and still no low beams. High Beams and running lights/turn signals work. Ideas? Checked both fuses for r/l low beams and the relay as well as the fuse/relay for the DRL are all good.
A: Both low beams are powered by a low beam relay that is turned on by the bcm.
If you have no power to both low beam fuses … move back to the low beam relay. Turn the headlight switch on and off … the low beam relay should click. If not, swap the relay with another relay in the fuse box.
If still no good … remove the relay … the relay socket should have 4 terminal pins … 2 pins should have battery voltage at all times. 1 pin goes to the bulbs, the remaining pin goes to the bcm. The bcm pin provides ground to close the low beam relay. If it’s not supplying ground the relay won’t close. If providing ground to the bcm pin makes the headlights work …. either the bcm is bad or the low beam switch input to the bcm is bad.