So I have been having a temp problem and just noticed my temp guage will sometimes ( right after start up) peg all the way to the right side of the guage before coming back down slowly. Anyone got input on this. I hope I don't have to replace the guage and it is a fixable issue.

Thanks!

 

The gauges themselves are seldom the 'problem'. And, since the needle actually moves and it is an electrical gauge, it is highly unlikely to be a problem with the gauge.

The most likely sources of your problem are that the temp sender is defective OR there is a problem with the wiring from the sender to the gauge. Most wiring problems are in the engine compartment, so that minimizes your work.

Make the following tests: Remove the wire/connector from the temp sender (engine cold, so you don't burn yourself). Now, turn the ignition to ON...but don't start the engine. Leave the sender wire loose and do not allow the connector to touch any metal on the car; this is the "open circuit" test. The temp gauge needle should have gone full-scale to the right. Now, touch the sender wire/connector to a ground point (any bare metal on the engine, for example). This is the "shorted circuit" test. The temp gauge needle should be at full-scale to the left.

If those two tests gave correct results, the gauge and wiring are fine; your problem is the temp sender in the cylinder head. If you had a jumpy needle during the last test (shorted circuit), then there is some kind of damage in the sender wire. Usually, it is a bad connection between the connector and the wire; or it could be a wire fracture somewhere inside the insulation. Repeat the "Shorted circuit" test and play with the wire while watching the gauge [get a mirror or some help for this]. With some manipulation of the wire, you should be able to determine the location of the damage to the wire.

 

Go to ths link below. Here's all what you need!
http://forums.corvetteforum.com/c3-g...-tell-you.html

 

Many thanks guys I will check this out tonight!!!

 

Ok, so key on disconnected not touching anything, the needle does not move, key on touching metal it moves all the way to the right.

 

When you were "touching metal", did you wiggle the sender wire around to see if it stayed to the right? If so, then your problem is a bad sender unit.

 

Ok! So I had a chance to mess with the car again today, I put new heads on and had to go with a smaller temp sender. I was just reading online and have a question! Does the guage take a certain sender? When I put aluminum heads on the car I had to go with a smaller sender than what comes in the stock heads. Could this be my prob?

 

Very possible. Is that 'sender' made to send a variable signal to a gauge? Or is it just a switch that turns on a "Hi Temp" light on the dash? If it was just sitting in the heads, you don't know what it is. You can buy a sender that is correct for your temp gauge and with a smaller threaded fitting.

Contact Willcox (CF vendor), they have some good info on this issue.

 

I got it from Oreilly's it looked the same as the one that was in the car wheeI got but smaller and had a flat connector. I was having the same prob with the previouse one too and the guy I got the car from I believe said it never worked while he had the car. I will se if I can get a part number to post.