I have a 2003 GMC Envoy SLT with digital temperature controls. My problem is that my ax unit will turn itself on, change temperature, or change fan speed. This happens on an intermittent and annoying basis. So far I have changed the temperature actuator, and the digital controls unit. Same problem occurs... Looking towards the resistor pack next, but would appreciate advice.

SOURCE: need to find blower resistor for 2003 GMC envoy

ITS UNDER THE RIGHT INSTRUMENT PANEL.YOU HAVE TO MOVE THE GLOVE BOX DOOR.TO GET TO BLOWER MOTOR AND RELAY AND THE RESISTOR.

SOURCE: is it hard 2 change a coil pack on a 2003 6cly gmc

Not really. You have to remove the plastic air intake.

Duane Wong

• 6826 Answers
• Posted on Jul 08, 2010

SOURCE: HOW DO I CHANGE MY FUEL FILTER ON MY 2003 GMC

Fuel Filter Removal & Installation 2002-2004 To Remove:
NOTE: If a fuel filter is restricted, clean and inspect the inside of the fuel tank.

1. Relieve the pressure in the fuel system.
2. Lift the vehicle.
3. If necessary, remove the fuel tank shield from the frame.
4. Make sure the fuel pipe and hose connections, as well as the surrounding areas, are clean.
5. Disconnect the fuel pipes from the fuel filter; keep the retaining clips with the filter.
6. To avoid fuel loss and fuel system contamination, cap off the fuel pipes. Fuel filter removal and installation
   
   
7. Remove the screw from the fuel filter bracket.
8. Remove the fuel filter from the fuel filter bracket.

1. Install the fuel filter into the fuel filter bracket.
2. For vehicles with a 4.2L engine, install the screw into the fuel filter bracket. Torque the screw to 13 in-lb (1.5 Nm).
3. For vehicles with a 5.3L engine, install the screw into the fuel filter bracket. Torque the screw to 106 in-lb (12 Nm).
4. Uncap the fuel pipes.
5. Connect the fuel pipes to the fuel filter.
6. Turn on the ignition for 2 seconds, with the engine off, and then turn off the ignition. After 10 seconds, turn the ignition back on with the engine off.
7. Check for leaks in the fuel lines.
8. Lift the vehicle.
9. If previously removed, install the fuel tank shield to the frame.
10. Lower the vehicle.

wyet

• 510 Answers
• Posted on Jun 29, 2011

SOURCE: 2006 slt gmc envoy ac problems vent controls anbd

{: ) The popping sound you heard is caused by the sudden movement of an HVAC door, most probably coming from the recirculation door actuator (right dashboard area) or the mode actuator( mid dashboard area). The fan outputs could be normally working, but is being muffled by the incorrect positioning of the HVAC doors, giving an impression that there is fault in the blower controls. In other words, your vehicle is having an air distribution issue.
If there's no conflict in your climate settings, then the trouble may be in the HVAC doors binding or broken, or the actuators faulty or sticking. In both cases, servicing may involve removal of the dashboard to access these HVAC components.

SOURCE: where is the air tempture actuator located at for

Assuming you're talking about the HVAC mode actuators, below are a couple of diagrams showing the location of components in both the front and rear HVAC units.