If you find that the dome light and headlight buzzer don't work when you open the driver's door, but the dome light and puddle lights do work when the passenger door was opened: Check for shorts on the puddle lights. From the driver's door switch these lights get driven through a small trace in the buzzer relay, mounted on the same bracket as the cruise control amp. On my car one of the lights had come loose, smahed when the door was shut on it, and then shorted out. This blew up the trace inside the buzzer relay. Good news is you can repair it with some wire.

-Jason

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.