I have followed all the tests in a ford manual and still can not get the air to change from cold to hot. I have tested all conections from the the fuse panel to the cold/warm contol down to the blend door actuator. All tests ,volts / ohms/ grounds have been within specs according to the manual. I have even replaced the blend door actuator motor. One other thing is I removed the actuator motor and while it was plugged in turned the contol from cold to warm the motor turned all the way one way but does not go back.I am at a bit of a loss any help is much appreciated.

 

the little gear box on the drive may have gear stripped inside.

 

When I took mine apart the door was cracked. There is a "sleeve like hole" on the bottom of the door. That hole sits on the gear (more like a peg) that is turned by that actuator (motor). Mine had cracked at that hole and the gear would spin, but could not turn the door. Sucks, but that thing will crack and expand where the gear can not grab it.

 

I have a brand new actuator motor and with it out and just plugged in the motor turns clockwise and the stops , no matter what the temp setting is on the control it does not move which would lead me to believe that its a issue with the temp control but all the tests i did on it come out fine. I tested the ground , power and resistance according to the service manual and all tests meet the specs in the book. Any other ideas?

 

read down a couple paragaphs. it describes the variable voltage to the unit that moves the door, and the voltage you should get.. Might help.

Sparky's Answers: 2004 Chevrolet Tahoe Blows Hot Air