I have a 02 GMC HD. My blend door does'nt seem to be working. It just blows out on the floor. I did pull out my center console to put in a center seat. Their was ducting in the console. Can anyone give some help with this?

Have seen this issue several times. Occasionally mode door actuator was failed. Most of the time the seals come off the mode door causing it to stick to the case and when the actuator forces it loose the cam/ gear portion of the actuator comes apart causing no mode door operation.

Sounds like I have to pull the heater box out to fix this problem.