This summer the factory temperature gauge pegged to the hot side then when i went to start it again it did not work at all.I thought the gauge was bad so i got a new one ,no good.We checked all the wires ,ground,printed circuit board everything checked out ok.Even got new sending unit,no good.When i start the car up gauge moves to half then goes back down,so this tells me gauge is ok.any ideas?Ihave under dash gauges so no big deal,but i still would like to have it working.

Does the gauge peg-hot when you ground out the wire on the sending unit?

Yes it did.Could i have a sending unit for idiot lights?

That very well could be the problem but I would think that the gauge wouldn't do anything unless there was an overheating condition.
(I've never tried it)

So do you think i have the wrong sending unit?

Gary,gauge going to full "hot" with sender wire grounded indicates the gauge is working as it should. Could possibly have a sender for lights instead of gauges.Though they look quite different.

Gauge sender pic>>>http://www.standardbrand.com/web_app/catalog/smp_bgbulk.aspx?strSearch=TS-6


Idiot light sender(switch) pic>>>>>http://www.standardbrand.com/web_app/catalog/smp_bgbulk.aspx?strSearch=TS-25

First, did the gauge ever work correctly?
When i start the car up gauge moves to half then goes back down,so this tells me gauge is ok.any ideas?
Is this a factory gauge car or was it converted to factory gauges? Idiot lights cars ground the temp circuit to make the temp light come on when the car is cranked. If the car was converted to factory gauges and the idiot light harness was used (converted) the gauge will peg to full hot when car is cranked. To stop this there is a 20g DG going from the temp circuit to the IGN switch. Cut this wire to prevent the temp circuit from being grounded when car is cranked.

If your car was converted to gauges and the 20g DG is still there, the gauge should have been pegging to full hot. Since it only goes half way indicates you have high resistance in the temp circuit somewhere. Check your connections at the gauge and at the PCB connector.

Yes my car does have factory gauges ,and worked perfectly until july.Like i said it went the whole way to hot,then with the next start up nothing at all. Thanks for the input.