Start the car for the first time on a given day. Early morning, middle of the 100 degree afternoon...doesn't matter. The temperature gauge works fine. Good readings, etc. Shut it off, restart immediately, much later...the guage refuses to read. It pegs below 100 degrees.

Anybody got any ideas? Oh, the sensor HAS been replaced and the connection HAS been recrimped and is tight.

HELP!

 

Maybe a break in the wire somwhere ? Ground the wire to the block & jiggle it around some (to simulate hitting potholes & such) while, having someone observe the gauge. If the wire & ground is good, the gauge should stay pegged during this. The wire runs from the sensor, thru the firewall at the bulkhead & to the gauge. There could aslo be a bad contact at the cluster on the harness plugs. Somewhere, the connection is being lost.

 

Now we ARE talking about the TCS on the drivers side just under the heat shield right?

And you said ground the wire. I assume the end that is connected to the sensor....

 

An update on this. I checked the reading of the TCS with an ohmmeter. The resistance steadily drops as the engine gets HOT which is to be expected from a thermistor.

When I ground the lead going to the gauge, (grounded directly to the negative terminal of the battery), the gauge reads either 100 degrees or 220 degrtees (has read BOTH at different touches). I am going to ASSUME from this that I have a bad gauge.

Can anyone dispute or cast any other assumptions for me?

Also, can I buy just the temp gauge itself or do I have to buy the whole instr. cluster?