Quote Originally Posted by MFritts
Ok, checked voltage at all fuses, everything looked normal with key in acc. pos, "on" position, and car running with the exception of a -.2 voltage (compared to other fuses) on #'s 10 & 11.

Even swapped out the Sylvania Silverstar bulbs I put into the low beams last fall with the old ones that I got with the car.

If anything, the temp drop seems to be getting worse the more I futz with it! Got it down to -32F last night...and the temp drop is progressive - mess around, test, lights on...turn lights off...mess around, turn lights back on, and temp drops another 20 degrees...argghh!
Ah! Your temp sensor has a total failure or something going on - the way it's creeping lower like that - there may be a break or something in the cable that only shows up when the engines running & causing vibrations.