i just bought a 1990 gt a couple days ago n i dont no really anything about mustangs. Well its pretty cold right now and my heater doesnt work and i have no idea why.... can someone give me some sugestions?

 

with the engine up to operating temp, feel the inlet and outlet hoses that go to the heater core. If they are drastically different, it's clogged. If they both are warm, you probably have good flow and have a baffle / HVAC door problem.

 

Or you heater core leaks and someone just bypassed it, or you have no thermostat.

 

start simple replace the thermostat and make sure it faces the correct direction

 

aright thanks i will try all this

 

post back if any of this works, bc my girlfiends honda passport is havin the same problem
and i cant figure it out!

 

How about..


Add some coolant..


If your heater core has no coolant in it, then it won't get warm..



JT

 

Yeah, good point. I had a car that the temp gauge got hot, but the heater core didnt. Had a coolant leak, and when the level got too low the heater wouldnt work, but you couldnt tell it was low by looking at the gauge.

 

what if it the thermostat has been replaced and the system has been flushed and heater core is good. What could it be then?

 

no coolant or low coolant = no heat