When i turn my heater on it blow out air on lo speed when i put it on hi hot air move to the defoster

If your a/c compressor kicks on and your manifold gauges show proper hi/lo readings then I would inspect the blend door. The blend door is a motor that moves back and forth when u set the temp for hot or cold . In your case, it may be stuck in the same position. The blend door is located in the dash, usually behind the glove box or in that general area. I hope you are able to fix your problem. Scott

problem 1 could be a loose wire, but if it is failure in the switch it will need to be replaced cleaning is probably not an option. Problem 2 bad gas can cause the stopping at idle speeds add some stp fuel treatment, read label to make sure it dries up water in gas. Fill up after you add the treatment and you will probably be good. problem 3 is tricky. Try turning off the a/c then turn it back on you should hear a little click like sound which should indicate if it is in fact turning on the a/c. If it sounds like it did turn on then turn off a/c and switch to heater or vent mode you should hear what sounds like little doors being closed. If you don't hear a change or heater doesn't blow hot air or your outside air vent doesn't blow cooler/outside temp. air then you may a have a leaking vaccum line or the vaccum unit is not working right.

Need more information. The most important thing would be to watch the heater water valve move when someone turns the control from hot to cold, back and forth?
Heater valve controls tend to be operated by vacuum, and switched by a heater computer. Lots of possibilities. But first tell us what you see move when operated? Valve is usually in engine compartment, in the heater hose. Follow the hot one.

you need to check under dash to make sure plastic heat pipe is in place to that vent

sounds like a blend door problem... find lever to blend door disconnect it move lever back and forth and see if it changes anything...

U have a bad temp selecter cable.....or control knob itself....u can reach to the left side underdash and open vent by hand and it will stop the heat....i once installed a vent pull out type cable ..like the cars in the 70,s and it allowed me to open and shut vent for hot/cold....but either way your cable isnt opening air vent...GL

Sounds like a thermostat sticking. Some things to do. First check coolant level is up and moving. Second (most likely), change thermostat. Very easy fix for backyard mechanic. Make sure to put thermostat in so water flow is correct direction. Look for arrow on side of thermostat. Next, is belt to water pump loose. Another easy fix in most cars.

Check blend door motor for proper operation (vacuum operated) if necessary, detach arm from heater box and move by hand. If you have heat then, change motor! You are reaching operating temp for engine, right? If not, thermostat is stuck open... Change.

Replace the temp control on this car, it should be electrical control not cables.

working on 4 and 5 speed that the resistor that broken cold air you got to move the selector to see the motor that move the trap hot and cold sometime when the motor was not move to the hot side for a long time its jam the motor on the passager side under dash put to hot and gently tap the motor tanks pierre