Heat and Temperature Gauge

[dirtriderdd]

My temp gauge stopped working. I replaced the sensor and thermostat (thought perhaps it was stuck closed). Still not working. I put a jumper wire from the line to the block and the gauge maxed out. So I believe the gauge is working.

Coincidentally, my heat is not working. Could these related? Any ideas?

thanks.

 

[1987 GMC Jimmy]

Absolutely. By the way, a stuck closed t-stat will overheat you. A stuck open one will underheat you. I'd get you a good infrared non-contact thermometer and point it at the side of the head where your sender threads in. What temperature thermostat did you put in, and I know this is a dumb question, but is it pointed in the correct direction? Is your coolant clean and properly filled with no air pockets? Flushing your coolant maybe a good idea. Cooling systems that are sludged up, especially the heater core, don't work right and it can all run cold. My brother's Dodge does exactly that. You open the radiator cap it's just brown goo, and you can drive that thing 100 miles, and the best it'll blow is lukewarm air. Prestone sells a little three dollar kit at Walmart, and all you need to install it is something to cut rubber and a flathead screwdriver. All you need to make it work is a garden hose. I've got their little flush kit on both of my rigs.