Heater not working properly

http://realfixesrealfast.com/realfixesrealfast.com/Heat_%26_Air/Pages/HVAC_Mode_Door_Problem.html

flapper door inside duct work not opening and closing properly. check my tips section for heat diagrams

Most likly this van has seperate controls for driver and passenger heat and ac controls.If its blowing hot air your heat is working.These controls operate differant dampers that are electonicly controlled.If the dials arent working they would cause this problem.

The heater resistor is probably faulty, its located near the blower fan

hi from uk the problem your symptoms describe esecially the bubbles that are appearing in the coolant header tank would suggest that the poor heat in car is due to air locking in the heater and this is most probaby the air bubbles you see in head tank are also finding their way into heater matrix via heater hoses may i suggest that asap you visit garage for a cooling system pressure test because theseair bubbles should not be appearing and is a sgn that you may have a cylinder head gasket in early stage of failure and what these bubbles are is compression in cylinder/s is leaking via gasket into the coolant system and emmiting in the head tank however i do say early sign so a compression test on cooling system will confirm whether or not ? considering cars age? it is not uncommon especially if high milage or any history in past of overheating ? hope this helps

I have a 70 mustang that did that. My problem was the core was clogge and the water couldnt circulate through properly. I took both hoses loose and sprayed the garden hose through each one to clean out the system. took about 10 minutes but my heater started blowing hotter air. you can use a spray gun on the end of the water hose when you point it in the heater hose. dont use a high pressure hose, just a garen hose with a sprayer on it.

The heater/AC temp control blend door is warped and sticking, this is a very common problem in this series of mustang, in order to fix it the dash must be removed.

need new technician.if the blower motor works even with only one speed than the blower motor works and did not need replacement.sounds like blower motor resistor or resistor wiring,when there is a problem with the resistor or wiring you will only have one speed,this way you atleast have heat.so if your tech replaced the blower motor when it worked and did not need replacement then it sounds like he is just throwing parts at it,you have to wonder if he really checked anything.have the resistor and wiring checked and if ok then check the heater control head and wiring.

hi check the resistor pack located near the heater motor.this is by passed when heaters set to max so they work.

I had the same problem and the gear box that opens and closes the valve for the water flow through the heater core was stripped. I had it replaced because it is a bear to get to. Hope this helps.