I just bought a 1994 half ton with a v6. the heater doesnt get hot. truck has a newer radiator and i just replaced that thermostat yesterday with a 195 unit. still no heat. fans blows but blows cold.

Heres the crazy part. i let the truck sit here at wotk and get warm, temp gauge just over 200, the upper rad hose was warm, both heater hoses are warm, but the lower rad hose was cool to touch, also that antifreeze in the rad was cool enough i can put my finger in it with no problem.

any ideas?

 

Radiator is doing it's job.

Getting all the air out of the heater cores on these trucks can be fun..... Also may be a blend door problem, if you have A/C, you can't get to it without pulling the dash, and then heater box.....

Might also try adjusting the temp control.... procedure is posted around here somewhere.....

 

Was the stat boiled to verify its working prior to install?