Why does my GMC Sierra 1500 blow cold air?

The dash vents do not blow any air. It seems like a common problem. Im gonna go ahead and replace the mode actuator! A/C only cold on passenger side. Drivers side blows hot. There is no adjustment on the drivers side for temp. If you turn off the truck and then restart, it might work for a bit or not.

Where does the air come from in a GMC Sierra?

This 2005 GMC Sierra came in with the complaint that the air will only flow from the defroster vents, regardless of where it is commanded to. This Sierra has auto a/c controls and no floor mounted center console.

Why are the vents on my GMC Sierra stuck?

The most common symptom of course is lack of control over the vent output position and normally it will be stuck in the defroster only position. If it is not currently stuck in the defroster position but you are changing the actuator anyways. make sure that you set the vent position to defrost before starting this procedure. You will see why later.

Why does air come out of the defroster vent only?

At light throttle or when you were on level ground, it was ok. Start up a hill or give it gas to pass someone and the AC would start blowing out of the defroster vents. It still used vacuum. Had to have it fixed one time. One vacuum line from the rear of the intake runs to the control valve under the dash. It must be different from the trucks.

Why does my GMC Sierra 1500 not turn on?

Air blows out the vents for about 20 mins, then it starts blowing out slower and soon it is blowing out in the ducts, but not coming out anywhere, (vents, defrost or the feet ) . Won’t switch from,cold to hot, stays on air conditioner all the time, won’t switch to heat, replaced the blend door actuator and it still does it.

Why is my car blowing hot air and cold air?

Blend air door is the reason for drawing hot air to cold air in your car system. This door is located in the ventilation system. The hot air is blown directly from the engine if the blend door isn’t working properly.

How does the hot air blow in a GMC Yukon?

A small servo motor that turns hot and cold air valve in the heater box. I pulled the small flat motor off and noticed the shaft was jammed and would not turn when i moved the temperature selector knob from hot to cold.

Why is the heater on my GMC Sierra not working?

Have a 2000 gmc sierra. Heater not blowing out hot air. Both input and output hoses hot. Can air . On hot it is just blowing lukewarm air . Putting hotter. Temp gauge is registering just below 210 Could be 2 things, one would be a bad temperature valve, a plugged heater core, or a blend door actuator.

What happens to the temperature in the car when the AC is not working?

The temperature in the car can rise 20 degrees in just 10 minutes on a hot day. The windows open will definitely ameliorate this problem somewhat when your AC doesn’t work, but you know that on truly hot days that just barely takes the edge off.

Why does my car make a knocking sound when I open the door?

When you start the car, or just the AC system, and notice a knocking sound like someone tapping on your door, that is indicative of a problem with the blend door actuator. Inconsistent Airflow: If the blend door is moving back and forth, then the airflow will be diverted incorrectly or maintained incorrectly.

What causes a blend door actuator to fail?

If you cannot move the blend door an obstruction has gotten in the way of the door movement which will make the new actuator fail. These obstructions can include: pen, tooth pick, small toy or bubble gum to name a few. If the door is stuck the heater plenum with need to be removed and the problem resolved before installing the new unit.