79 vette temp gauge

[Glenn28132]

I have a 79 vette I checked the temp of the car running with a/c on in stop and go traffic. I taped my thermometer to the upper rad hose the reading on the gauge inside the car was over 220 allmost to the red mark. the reading on my thermometer taped to the rad hose was at about 180 degs my question is what do i do to get the problem correctedwhere my gauge inside the car is working correct

thanks

Glenn

[Ed Jennings]

Re: 79 vette temp gauge

You could have a wiring problem, but more than likely you need a new temp sender. The senders GM supplies are notorious for inaccuracy. I'm not sure if the newer cars use the same sender as the pre 70's cars or not. If they do, there are aftermarket replacements which are more accurate. Wells TU5, available at Autozone (and others no doubt) works well in most older cars. Resistance at room temp is about 700 ohms. Again, this info may not be relevant to the newer cars.