Heat not working

hicago Electric Harbor Freight Mig Welder On Off Power Switch Parts.

first check temp gauge on dash is it normal if so termostat is fine than check the heater hoses going inside from engine compartment if they are hot rule out control valve if it in the engine compartment sit in the vehicle and listen for any noise when you move heater temp switch from cold to hot if you hear clicking noises and no change it may be blend door accutator with moves when you slide or turn heat control nob the heater may have to be removed on some models eexpensive repair may be needed

you might have air in the heater core if you let your antifreeze get too low. it might be too low now. maybe the temperature selector cable is broke and flap is closed to let heat come through. could be thermostat is stuck open and engine can't build heat. heater core might be plugged.

I just repaired one with this problem. The selector knob for heat/cold was cracked inside where it slides onto the stub that sticks out of the dash. It felt like it was working, but really it was in a bind and just felt like it was working. Also, there is a selector that diverts the hot air into the cabin, or it lets outside air in, or it recirculates the cabin air. I think the selector knob is your best bet. Mainly because the heat is working and the air is not. If it happened to break while on heat, the ac will not work when the heat is on. You can try to switch the other selector to defrost and see if the ac compressor kicks on. There is also a fuse for the compressor, so check that. If all that checks out fine, check out the diverter in the dash. Usually this is vacuum operated, sometimes electric. But, if it is vacuum, the problem may not be the unit itself. It can be a vacuum leak somewhere under the hood that is leaking so much vacuum that there is not enough left to operate the other accessories. Sometimes on older vehicles, the vacuum hose will split where it is slid on a connection. The connection, or tube is usually somewhat larger than the hose and being in a stretched position for years and exposed to the engine heat, it will finally fail. Most times when this happens, you can take the end of the hose off of the barb fitting, cut it off just above the split, and install it back on the connection or fitting. I would check all the hoses in the vicinity of the engine and look at the ends of all of them. Your engine may still run, but that is because there are "limp" modes built into the computer controls that allow the engine to run without some things. My first thing would be to check out the dash selector, just pull the knob off and you can turn the stub with a pair of pliers and see if that does it for you. Then, you can check the fuses, Switch on defrost and see if compressor kicks on. If it does, check vacuum lines. The part in the dash hardly ever needs replacing. I have some thirty some odd year old trucks here and that is about the only part that has not been replaced on them. Then, if all that checks out, are you sure the charge is ok on the ac? The low pressure switch, which is plumbed into the ac system, may have the ac shut down. But, make sure all the other things are checked out first. On a Ford, you can un plug the low pressure switch and jump between the two wires with a jumper wire and see if the compressor kicks on. This can be done without the engine running, you will hear the electric clutch on the compressor engage when you jam the jumper wire in with the key on. Be sure to un do it shortly because will drain your battery, and if it is on a low charge situation, don't run the compressor without enough refridgerant.

Where is the clicking noise coming from, the engine compartment or the dash panel? Probably not the heat selector switch, so I'm willing to bet the thermostat is sticking and not opening, which is lesding to you not having heat and the clicking noise you are hearing. Replace the thermostat.

It's a definite possibility. Make sure your coolant level is good. Is the engine temperature coming up on your temperature gauge? If the engine temp is low and there is no heat in the cab, it's most likely a thermostat stuck open. If your engine temperature is good, but no heat in the cab, then it's probably something else like a plugged heater core, kinked hose to the heater core, or even your heat selector switch not working properly.

Not much information to go on here.Thermostat if your heat gauge isn't showing a warm engine. Coolant level too low. Blower motor or fan switch. Heater core. Heat/cold selector door not operating properly...

Forget the Thermostat.
Start with no $.
Check Heater Core, leaks in rubber hoses ( they go to the firewall, should be hot when touch them (2) ) Coolant Level.

approx. $200-250 - takes less than an hour to replace if that part is the problem

Possibility your nob/resistor in the nob is bad. The resistor changes current in corolation with nob position.