OK so I'm new here and have a 94 mustang v6. The heater does not get hot. I replaced the thermostat, but still cool. I pumped water in the in and out tubes of the heater core, thinking it was pluged. BUt still no luck. So if any of you know what else I could try that would be awsome.
Ok, i was just having the same problem. Since you replaced the thermostat, did you "burp" the system? There is a bolt on the top-front of the engine (youll know its the vent, it says it right on there), with the engine running, open it very slowly until a little coolant comes out, then close it. ALso, what temp thermostat did you put in? I know I replaced a 195 with a 192, the 195 was old and it let water creep by. Make sure you bought a good one, mine costed $12. I also replaced the Coolant Temperature Sensor (NOT sender). After a few times of running the car from cold to hot, I get nice warm air. I think the main problem though is you have air in the system, get that out, and youll be fine.
So the car gets up to temp but it blows cool air still. I put 195 degree thermostat in, but befor we did that we tested it, by boiling it to make sure it would open, and it did. So I'll try burping it and see what happens.
Mine blew cold when the thermo stuck open, but the car didn't get up to temp since I was driving all highway at the time. Let us know if removing the air works.