Remove door panel from a 1992 GMC sierra 1500

SOURCE: removal of power steering pump on 1998 GMC Sierra 1500

you need a power steering pump puller the rest is simple any trouble let me know

SOURCE: How to remove a front door panel from a 2001 GMC

On the inside trim, you can remove screws that are by the door handle, arm rest, under door and side of door and then gently pull back on the panel as there will also be retaining clips attached and you don't want to break them. You'll need to lift the door panel upwards in order to get it off the window ledge.

SOURCE: how do you remove the door panels from a 2001 GMC

On the inside trim, you can remove screws (these screws may be covered by filler pieces or may be visible, or they may require you pry a plastic piece off that covers the screws) that are by the door handle, arm rest, under door and side of door and then gently pull back on the panel as there will also be retaining clips attached and you don't want to break them. You'll need to lift the door panel upwards in order to get it off the window ledge. Then you'll need to manipulate the panel and disconnect the door handle linkage from the door handle and disconnect any other wiring that may be attached to the door.

SOURCE: how to remove door panel of gmc sierra

http://www.gm-trucks.com/forums/index.php?showtopic=69225&st=0&p=508856&

SOURCE: 2004 gmc 1500 sierra heater control stuck on

Defrost is the default position. Is the control a autyomatic temperture control unit? ( you set the temp and select automatic) if it is the system is completely electronic. You push the buttons and the control still says defrost or can you select something else and the control shows it but it just keeps coming out the defrost? If the control changes and the air comes out the defrost anyway and the cheack engine light isn't on, then the problem can be blown fuses or an air door actoater not working. Does the dash emit a clicking sound? if it does with the covers off the bottom of the dash reach around touching the different pieces till you touch the idem that is clicking. this is an acutor motor, or blend door motor. they have gears in them that wear out and break the motors aren't repairable and you just replace the ofending motor. the door that is moves can be stuck. and may have to be freed up with blaster, WD40, or other rust buster till it moves easy. maybe after getting the door to move smoothly you can get the old motor to move the door wiithout having to install a new one.