Originally Posted by stegarsla
When it'* hot or partially hot and I stop and restart the engine, it will take lots of time before the climate fan turns back on, even if the climate control thingamajig give 5 "dots" of fan speed.
What causes this? Is it normal and it'* just bad programming from GM?
Does the motor spin freely? Run on HIGH and then turn the button to OFF and see if the fan stops quickly llike it might have dry bearings? Do the motor seem to start after hitting a bump that vibrates it? Does it start running if you tap gently on the housing on the firewall--the plastics get brittle with age, so handle with care.
My first guess would be a bad connector at the blower control module (electronic part replacing a resistor pack in the manual controlled unit). Try pulling off the connectors and checking for heat and corrosion damage.
My second choice would be the blower control module itself. They fail in different ways. Some give different speeds than they used to give with the same number of bars showing. Others stick in the ON setting the blower continues to run even when the key is turned OFF. Some won't run.
The blower control module is on top of the air passage next to the blower. The relay center can be loosened with a couple of screws and lifted slightly against the wiring to it and make room to access the screws for the blower control module.