The temp guage on my 1998 Merc Mystique Zetec keeps dropping down and coming back up to normal operating temp. I've had the thermostat changed, so that's not the problem. I was told that it's probably a bad sending unit.

My question is, which sensor is the one to the temp guage on the dash? There's one on the top of the thermostat housing and one under it.

If someone would happen to have the part number, I'd appreciate that as well.

Thanks everyone!


'98 Mystique Zetec w/ auto trans 103,900 miles Kenwood KDC-MPV7017 CD/MP3 HU Kenwood KFC-6889ie 6x8" 3-way speakers '96 Mystique Zetec ATX 108,000 miles