Cold Weather Headlights

I have a 2003 Toyota Corolla that runs great except when the temperature is below ~15 degree F, the headlights automatically come on despite the car being off. This usually happens in the middle of the night and the headlights are on in the morning when I awake. I brought it into the Toyota dealer and they claimed they’d be unable to help unless I could replicate the problem. Anyone have any suggestion?

That’s a strange one!

Have you ever caught the lights coming on, or are they just on in the morning? Is the battery dead, as if the lights were on all night? Once you drive the car around, can you shut them off?

I would replace the relay. It might be the switch, but I suspect it is the relay.

Your question doesn’t match my answer. Wanna try another question? No? OK. When the headlights come on by themselves, can you tell if they are the DRL (Day Light Running) lights? When you pull the parking brakes, it keeps (supposed to) the DRL from coming on. When you park the car, pull the parking brake handle. If the lights still come on, ask another question. The headlight relay may be the cause. If the headlights still come on, after pulling the parking brake handle, pull the head light relay. It’s probably under the hood. Next question.

Thank you for the reply. I’ve never actually witnessed the lights come on since I believe they are coming on in the early morning hours when it is the coldest part of the night. When this first happened to me, the battery was dead and I had to jumper the car to start it (probably slept in late that morning). After I figured out that the lights were coming on (by catching it some mornings before the battery was dead), I started disconnecting the battery negative terminal on nights I knew it was going to be cold. Of course, this solved the symptom but not the problem and is a tedious work around. Once the car is started I am able to shut the lights off. Also, strangly enough, if I toggle the hi beams switch before trying to start the car, it shuts the lights off…

OK- thank you. I’ll try this. Just surprised the dealer did not recommend this…

Not sure if this posted. Thank you for the reply and I’ll try the relay. I am surprised the dealer did not recommend this since it seems fairly easy to try…