Son's car - 1998 Ford Contour SVT
Spuriously, and only during cold weather (~30F or colder), the low beam headlights come on. This is in the driveway, not while driving. (This car has separate bulbs for Low and High.) He can disconnect the battery or remove the low beam relay to get them to go off. Or sometimes if he leaves the headlight stem forward (Hi beam position), the lights do not come on.
The battery has been drained several times over the last 2 or 3 years. He has swapped relays around to try to get it to stop, but with no success.
Other pertinent (probably) information - about 4 years ago he had a front end collision that messed up the radiator, AC, sunroof, etc.
I suggested that cold weather also means salt and brine on the roads which could possibly be setting up an electrolytic situation leading to a short. (I have no idea if that could really happen.)
Any suggestions on how he can proceed with troubleshooting? He likely won't take it to a mechanic. Would a trained professional have any special tools or techniques that would help pinpoint the issue?
Thanks, Craig