My 1984 car’s headlight (driver’s side only) turns on by itself. The switch is always in the “Off” position when this happens. My mechanic is stumped. Any suggestions?

The most LIKELY suspect is the switch, especially if it is a “combination stalk switch” mounted on the steering column…You need a wiring diagram for your car so you can determine if the right and left headlights are wired independently to the switch or at some point below the switch (a headlight relay??) is the point where the right and left split. First, I would locate and replace that relay before I replaced the stalk switch…It’s one or the other…

A lot of ‘foreign’ cars use a separate relay for each headlight. I think you may have a failing relay for that side. If the headlight switch was acting up, I think both headlights would be acting weird.

Another possibility is that the relay is good, but the ‘coil’ wire that triggers it is being shorted. I would assume that this would be wired so that a ‘hot’ connection to the coil would energize the relay, and in this case, it would be difficult for this to occur, but if it is wired so that the headlight switch grounds the coil wire for the relay to energize it, the wire could easily be shorting to ground somewhere and turning on your headlight on that side.

Getting a wiring diagram for your car would be useful.