Just purchased a 1989 GT and I have a quick question about the temperature gauge. All of the gauges on the dash work correctly except for the temperature gauge. I was wondering if anyone had some advice on what I should look for to fix it. Thanks in advance.

 

How is it failing? Is it always pegged hot, or cold, or somewhere in the middle?

 

It is all the way at the bottom. It doesn't move when I crank the car up.

 

You just need to track down the system and see what is failing. Could be the gauge or wiring. Locate the temp sensor on the engine and see if it is hooked up. Hopefully the computer is still reading the engine temp so the air/fuel will.be adjusted properly.

 

These cars don't use the same sensor for the gauge as they do to read coolant temp for the computer. They have separate sensors for that.

OP the sending unit for the gauge is on the drivers side front of the lower intake. It will have 1 wire attached to it.

This one


The other one is the ect on the passenger side , and is what tells the ecm what the coolant temp is.

 

Thanks for the info. The dash gauge sensor is attached by one red/white wire. I was told that if I ground the wire and turn the car on, the gauge should shoot all the way up if it is working. If not then there is a wiring or problem with the dash gauge itself. If the sensor does go all the way up then there is an issue with the sensor itself and that needs to be replaced.

I haven't checked the ECT sensor yet. I will do that first thing when i get home this afternoon. I want to make sure that is attached. Is there any way to determine if that sensor is working properly? From what i have read, it is very important.

 

The ECT has nothing to do with the gauge on the dash , its sole purpose is to report coolant temps to the ecu.

 

Grounder the temperature sending unit and it pegged all the way up. Got a new sending unit and it works like a charm. Thanks for the info.

 

Glad it is working.....learned a bit myself too.