okay so here's the problem, I live in Wisconsin, it's -4 deg, and i don't have any heat. In the last month i've replaced the thermostat, the water outlet (i cracked the flange while tightening the bolts) andlower radiator hose (because of a pin hole the the old one). I pressre tested my cooling system and tested the coolant itself. Both were fine. I can't find any leaks and no i'm out of ideas. Anyone else have any suggestions? I'm cold. lol

 

have you checked you heater core???? that could always be the issue... its located behind the dash... i had a similar problem with a S -10 and flushed the system, replaced the thermostat, etc, never thought that it could be the heater core. some times condensation will build up...

 

Thanks, i'll try that tonight.

 

Have you bled your coolant system? Air will cause heat to fail. Remove the thermostat cap and see if it is filled to the top. Most likely no. Let it run for maybe 10-15 minutes with the cap removed. This should be enough time for the coolant system to cycle about two times releasing any air in the system.

 

you may also have low coolant so check that before everything as it might be as simple as that....