Heater works ok but wont send air thru defrost vents
I own a 1995 Pontiac Grand Am. The radiator cracked and I had to have a new radiator installed, yesterday, 31Dec08. With the new radiator, the heater works okay, but I cannot direct the heater airflow with the right heater control knob. The heater only projects an airflow through the instrument panel outlets. When I put the dial to defrost, no air comes out of the defroster vents, the airflow continues to come out of the instrumet panel outlets only. It is as if the control knob only operates in the "vent" mode, no matter where I position the dial.
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Great question dustin but the A/C is suppose to come on in defrost or mix mode- this is floor & defrost. Does not seem to make sense does it. One of the things the a/c does is remove the moisture from the air. You need warm DRY air to remove the moisture from the windows. An automotive H.V.A.C. ( Heating,Ventilation,Air conditioning) first forces air thru the a/c evaporator core then thru the heater core and out the selected vent. If you only want a/c a blend door will by-pass the heater core which is controlled by a hot/cold knob or digital temp cotrol on the dash. Now back to the cold air problem- assuming the basics are all ok- Coolant is full, Engine gets up to proper operating temp-around 195 degrees- upper radiator should be hot. Both heater hoses should be hot. If thats all OK the blend door might not be working. It is controlled by an electric motor called a Blend Door Actuator which are prone to fail. I have replaced many on ford vehicles. Hope this helps
If both heater hoses are hot, and the radiator is full of coolant, it may be a blend door problem under the dash. The blend doors direct air thru the heater core and out thru the vents. It may still be under Ford warranty.
first check to make sure that the hose,s back there didn't crack / of there fine then the heater core has blowen open and is know leaking / if you are in an aera that diesn't get real cold take the hoses off and route one to the other till you can get it fixed
If the heater coil was bad, it would be leaking radiator fluid... probably into your dash/floorboard (depending on where it is installed in your model car). There is a switch that diverts the hot radiator fluid through the heater coil when you want heat. There is also an air diverter valve that helps to mix the hot and cold air. The fluid valve is controlled by the A/C settings control. The one that you use to choose between heater/air conditioner/vent/ defrost. The air diverter is controlled by the temp mixing controller. The most simple explanation is that one of those valves or the controller of one of those valves is not working. If the hot water cant be diverted through the heater coil, the coil can't exchange the heat (warming the air). If the air diverter (hot/cold controller) cant move to add heat, then all you will feel is air from the vent side (from outside) or from the A/C cooling the air.
I would guess that its either a controller or one of the valves themselves. Odds are, it is a controller. That tends to be what malfunctions first.
its located on heater box, there are 3, what you do is watch each one as you move selector to vent ,deforost, hot cold etc, watch to see which one is no moving.should be on drivers side. hope this helps.