1993 Buick Regal Turn signals

Check for a bad ground on the left rear sockets. Sometimes when just the left signal is turned on, you might see the right side glowing dimly because current going through the left bulb can't get to ground, ... It finds an alternate path through the right tail light bulb.

You can also measure the voltage on the ground terminals of the left rear socket. There should be 0 volts. If you find voltage, look for a rusted ground wire terminal where it's bolted to the body, or corroded terminals in the socket.

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