Blend door actuator....

[Archaic2021]

So now that the miss is fixed it's time to tackle the a/c.

Air will only blow out of the deforest.. Does not blow cold at all....heat works and when changing to cool it will get cool air from outside but not cold. The compressor will not kick on although it's not locked up.

I figure first step is fixing where the air will come out all vents. The blower motor will change speeds.

Is it pretty common for the motor under the driver side near the gas pedal to go out...when I change from vent to floor to defrost it does nothing...just staying coming out the defrost on the windshield.

 

[deadbeat]

Mine was doing that exact thing the other day, take the actuator off and move the linkage by hand to make sure it moves free. If it does, check for power on the brown wire going to the actuator, if you have power there replace the actuator. If you move the linkage by hand and it doesn't change the air flow, check the door that the linkage hooks to.

 

[JeremyNH]

You don't mention year or model of truck. For the 1998 K1500 the one in the drivers side footwell is the mode door which directs air to which vents depending on the vent selector. It's the easiest to replace. The blend door is on the coil box in the middle of the dash and determines what percentage of air goes through the heater coil and vaporization coil to adjust outlet air temperature. That one failed on me and it's not too bad but you have to drop the dash to get the actuator out. The last is the recirc door which is in the passenger side footwell. That one controls whether air is drawn from inside or outside the cabin and is supposedly a real pita to replace. The blend and recirc actuators I know are the same. The mode actuator I believe is a different part number.

On my blend door I did perform a post-swap autopsy and found the main plastic gear was cracked. They're likely all made the same so a mode door actuator would be no more or less likely to fail than a blend or recirc door actuator. So swap it out and see if it fixes your position. It may be that the actuator isn't reporting the correct position to the HVAC module so the module isn't directing the compressor to turn on since defrost alignment isn't confirmed. But I'm far from an expert on it.