'94 K2500, 5.7L, Ex. Cab, AT, Base Model with power door locks, power windows. The AC / Heater is controlled by a module just to the R of the steering column. This module has a horizontal button / bar for moving the temp ^ indicator <----> across from blue ( cold ) to red ( Hot ). It has a fan button, AC button, and AC recirc button. This module has been replaced, I believe the problem is not this module.
Anyway, here is the problem: When I switch from normal mode ( either everything OFF, or heater on/off, directed towards the windshield or your boots ) to AC mode, it doesn't seem to want to switch cold air to the center vents. You can hear a kinda whistle sound for a long while, then you go over a bump or something, and all of the sudden cold air comes pouring out of the center vents. You can feel the AC engaging the compressor, you can feel cold air on your boots, but there is this delay, sometimes long, sometimes short, and then finally the cold air comes pouring out. Esssentially I believe the vent switching is sticking.
How does this work ? Anyone know of this problem ? I did replace this module with a junk yard one, but the junk yard truck was actually RUNNING AND I TESTED THIS MODULE FIRST. I replaced this module for a different reason, and it did fix that problem.
Anyway, here is the problem: When I switch from normal mode ( either everything OFF, or heater on/off, directed towards the windshield or your boots ) to AC mode, it doesn't seem to want to switch cold air to the center vents. You can hear a kinda whistle sound for a long while, then you go over a bump or something, and all of the sudden cold air comes pouring out of the center vents. You can feel the AC engaging the compressor, you can feel cold air on your boots, but there is this delay, sometimes long, sometimes short, and then finally the cold air comes pouring out. Esssentially I believe the vent switching is sticking.
How does this work ? Anyone know of this problem ? I did replace this module with a junk yard one, but the junk yard truck was actually RUNNING AND I TESTED THIS MODULE FIRST. I replaced this module for a different reason, and it did fix that problem.