Why is my front defrost not working properly?

If there is no clicking then, it still could be a motor problem but could be other issues too (less likely would be a blocked vent, etc.) The actuator isn’t really getting reset. The software in the A/C controls is relearning the stop points (at each end of travel) for the actuator.

Can a climate control fan only blow defrost?

SilveradoSierra.com • Fan Only Blows Defrost, Won’t Change To Floor Or Vent. : Climate Control Fan Only Blows Defrost, Won’t Change To Floor Or Vent.

What to do if your GM fan won’t defrost?

See if this fixes the problem. Many of GM’s AC control heads have a built in reset feature that when power is removed and then applied it will go through a cycle that activates all the vent doors and mode doors. It’s worth a try.

Is the Astro fan only blows defrost?

Re: Fan Only Blows Defrost, Won’t Change To Floor Or Vent. Yea the problem with them astro’s is the way the damn motor is crammed into the dog house with the heat it destroys the hard plastic vacume line . I have had 5 of them and every one had this problem until you change them out with rubber lines .

Why does air come out of the defroster vent?

u need to check the vacuum from the engine to the ac control head, the air defaults to the defrost when the system looses vacuum from the engine, this is for safety. You can’t post conmments that contain an email address. SOURCE: Air won’t come out of vents, but will from defrost and floor.

How can I Fix my defroster on my front grill?

I’m pretty sure the door that directs the air between the defroster and front vents is vacuum actuated. Check the vacuum lines in the engine compartment that go to the firewall. Find an approx 1/4″ rubber hose that goes into the firewall around the center of the firewall and trace it back to the motor and make sure it hasn’t come loose.

How does the climate system control the defroster?

The climate system is responsible for controlling the position of the defroster actuator which is connected to the air position door in the heater plenum. This actuator controls defrost, middle and lower air vents. When it fails it can do so in the defrost position and must be replaced.

What causes a refrigerator to not defrost automatically?

The electronic control board starts the defrost cycle and regulates how often they are triggered. If the control fails, your refrigerator can’t defrost automatically. The thermistor — also called the defrost temperature sensor — senses evaporator temperature and sends signals to the electronic control board.