New to the forum and looking for help with my temp gauge. It's pegged all the way up, but it doesn't seem to be overheating. It stays there after I shut the engine off. Changed the temperature sensor, but no effect. I recently had an issue with the fuel gauge and the solution turned out to be the ground strap from the frame to the cab, but that didn't fix the temp gauge to my dismay. It started out being an intermittent thing about a month ago but is now consistently pegged. Could it be the gauge itself? Can that be replaced?

 

Welcome to the forum

There are two temp devices on fuel injected engines
1. ECT sensor which is only used by the computer and runs on 5volts from the computer
2. ECT sender which is only used by the dash board gauge and uses 12volts
These two devices are not interchangeable

ECT sender will have 2 wires, red/white and black/white in 2002
Black/white is the ground and should be tested
red/white is the 12volt and should be tested, key on

The sender is just a variable resistor that changes resistance as it is heated up and cooled down

It is far more likely to be a wiring or sender issue than the gauge itself
If either wire is broken(unplugged) then gauge would show HOT with key on

 

Appreciate the help very much.