Quick recap. I purchased a 1994 truck 4x4. Temp guage doesn't work correctly. Barely moves off of cold and heater gets warm but not hot. Replaced thermostat tonight and heater is hot now and guage moves but not much more than before. Do you think I need a new temp sending unit? I'm gonna have to buy a repair manual because I don't even know where this is located. I think I'm also going to get an aftermarket temp guage. I'm just glad to have a hot heater. It was very cold today.

 

Update.... during the drive home from work today the temp guage was in the middle. I guess its good to go but I think I'm still going to get an aftermarket unit.

 

I ws going to say try putting a mechanical aftermarket gauge on there - even if it's only temporary to see for sure what kind of temp you are running. Also you could use one of those temperature guns and just point it at the radiator and various parts of the engine to see how hot it's running. At least you don't have an overheating problem!

 

After driving around town today it seems all is well. Nice hot heater and dummy guage is running just under halfway. Its nice to have heat again.

 

Did you burp the system completely? You may have an air pocket. Some of the gauges on the strippy models sometimes read funky. You can get a pocket thermometer and put it in the top of the radiator neck after the car has warmed up to check the actual coolant temp. Don't take the cap off when hot tho