I have a problem in which the headlights and all the other lights are always on (just like when it is dark outside. And...I don't like to use this word, but it is intermittent, sometimes it all works like it should. Anyone have a similar problem they traced to a switch/relay/sensor? Thanks. I found a similar thread in the "everything electrical" category and toastedoats was thinking about the ECC module or the sensor itself...is this the little dome (2) on the dash? Also, the moisture sensing wipers are in the complete off position. MODERATOR...I think I should have posted this in the electrical category...

The light sensor is NOT the little dome. That'* the thermal radiation sensor for your climate control. The light sensor is the little flat dime-sized sensor to the left side of the dash.

Ok...finally know which one is the light sensor (on the 99 PA it is in the center). The lights toggle on and off during the day. I have a 97 PA maintenance book and there are some procedures to help determine the problem. The fact that it is intermittent seems to point to a loose connection, which of course makes it even harder to pinpoint. Just am fishing for others who may have found something. Thanks.