Ok, strange temp guage problem
 

This is driving me nuts.....

The temp guage shows way in the red sometimes, but the car is actually running cold. Sometimes the guage reads normal. When it's reading high, if I turn my lights on, the needle drops and then goes right back up. When I press the window switch, same thing.

Now, I suspected a bad guage, but if the guage was bad, wouldn't it always do that? So I thought it's a bad ground somewhere and ran a ground strap from the battery to the block.
Didn't fix it.

This is the problem - when the guage does it's thing, I have no starter. Doesn't even crank.

I'm guessing that there are a gazillion grounds in the electrical system. Anyone have an idea where I should look?

Thanks :)

try a new sending unit

Why would I not even get a click from the starter motor if it was the temp guage sending unit?

bad battery cable connection? I'm just guessing

The sending unit cannot cause the starter to malfunction. The starter has nothing to do with a temperature gauge except they both draw current and current starts at the four ends of the battery cables and is distributed through the starter solenoid where the battery cable attaches to the solenoid. Try attaching the negative side of the jumper cables from the battery ground to the engine block and then I would also attach the positive side of the jumper cables to replace the positive battery cable. I'm thinking one of these two actions will fix the problem. If this fixes the problem take off one cable at a time to see when the problems return to figure out which cable is losing connectivity. The whole car draws the current through these cables which is why you are having problems throughout the car.

Tom