Heater blows COLD! Help

[kmsc90]

Okay, my heater blows cold air. I changed the thermistat and no luck, of course. I checked the hoses coming in and out of the heater core, they are both hot with good flow. I also noticed that the A/C kicks on and stays on. What is the deal with this damn Ford?

[AzTumbleweed]

What year is it?

[Intuit]

You probably need to turn-off the defrost on that damn Ford. Some model years also have a center push-button that activates the compressor regardless of what position the ventilation control is in.

Regarding the over-cooling issue, with some if not all models, they have a special, modified water-outlet that was designed with the intention on protecting the vehicle from being overheated.

To keep a longer explaination short, you probably need to replace the "water outlet". It contains a bypass "valve" that may have "activated" by melting; meaning you'll get a constant flow of coolant bypassing the thermostat.

This applies to '94 and '95 for sure. I'm not so sure with other model years, but they share a lot in common and so probably them too.

[Davescort97]

Welcome to AF. The A/C kicks in on any heater control position except the upper only and lower only vents. If it is kicking in on any other position it is supposed to operate this way. This dehumidifies the air so the windows won't fog up. On my Escort I have put a switch in the circuit so I can run the heater on defrost without the A/C compressor coming on. Better fuel mileage. If the air is blowing cold in all positions the fault is the vacuum operated blend door. The heater as you know has hot coolant going to it all the time. The blend door routes the air on through the heater core after it goes through the A/C core. There is one other thing it could be. It might be the cable that controls the heat has come loose at the bottom left side of the console. It is just to the right of the gas pedal. When you rotate the temperature control you should see it move.

[kmsc90]

Thanks everyone for all the advice! I do appreciate your time and knowledge.