Heater problems

The movement of air flow is most likely caused by a vacuum leak under the dash. The vent doors that direct air flow are actuated by vacuum. Check for leaks. As far as the temp control, make sure the switch on the dash is connected to the blend air door (under dash near heater core). This guide will help us fix it

https://www.2carpros.com/articles/car-heater-not-working

Please run down this guide and report back.

Feel the two heater hoses. They should be too hot to hold onto for very long. If they are not, suspect a plugged heater core. They can usually be back flushed with a garden hose. Pull the hoses off the engine, not the heater core to prevent cracking the tubes.

If the hoses are hot, a common problem is the electric actuators on the heater box.

Caradiodoc

Welcome to the site, your saying the blower motor stops blowing? Did you use a testlite and check the fuse circuits for voltage, when the problem is ongoing? Underhood fuse box, blower fuse 40 amp, hot all the time. Interior fuse box, 7.5 amp fuse, goes hot with key on. You can also use jumper wires from battery for voltage and ground to the blower motor connector, use inline fuse. See if the motor acts correctly? The speeds for the blower motor are controlled on the ground side, you don't need to worry about different speeds until you test the motor.

There is likely a problem of some kind with the blend door. It could be the control head, the actuator or even the door itself could be jammed or broken. That will have to be determined through examination.

Check that the cables are attached and functional from the heater controls to the door.

Could alos be a heater control valve used to shut the flow of hot coolant into the cab when the AC is running. It is usually located in a heaterhose. Could also be at the heater core.

Invest in a manual for this type of work. It is well worth the money.

Good luck and let us know. :)

Do you have a multi meter to do some testing?That would really help.

First thing unplug the blower motor put the fan on high see if you have battery voltage across the blower motor connector? I believe the motor is under the hood on the passenger side on that truck.

Are ou sure the coolant is full? Also, I need you to check somethoing. With the engine hot, running, the heater on high, feel both heater core hoses. THe should both be hot. Let me know what you find.

Joe

Do you mean that when you turn on the heat, you have air coming out of the vents but it isn't warm?
If so, check your level of coolant first (engine cold). If low, add coolant as necessary.
If level is fine, turn on the car and while it's idling, grab the upper radiator hose with your bare hand; do you feel coolant going through it? You shouldn't until the car has reached normal operating temperature.
If you do, your thermostat is stuck open and you need to replace it (typically this condition also results in your engine taking a very long time to warm up, and your temp gauge doesn't go up a whole lot, at least not to where it used to).
If you don't, the next step would be to find out whether your heater core is clogged. To do that, let your car reach normal operating temperature, then turn on the heat. Both heater core hoses (the ones that go in the firewall) should be very hot. If one is hot and the other is luke warm or even cold, your heater core is clogged and you need to flush it.
Finally, if everything checks out fine, you may have a problem with your blend door. It may be stuck on cold.

INSUFFICIENT HEAT
Ensure cooling system is operating properly. Check heater system hoses and core for coolant flow. Check for loose or misaligned cable to temperature blend door. And check blend door is not stuck closed

TEMPERATURE CONTROL LEVER
The temperature lever mechanically operates a cable to adjust the temperature blend door. Temperature blend door is in the plenum assembly. When temperature lever is in COOL position, temperature blend door closes off airflow to heater core. When lever is in the WARM position, air is directed through the heater core. When lever is in intermediate positions, heated air is blended with cooler incoming air to achieve desired temperature.