Heater blower won't run

[rquack]

2007 Buick Rendevouz. The heater motor does not come on to blow warm air into the cabin or into the front window defroster. I checked for blown fuses: all are OK.

Any ideas??? Is this a common problem??

[Tech II]

Well, the first thing to do is turn your car on....then turn the heater on, then set your blower for a set speed...if no air movement, take the handle of a screwdriver and hit the housing of the blower motor with it...if it then runs, you need a new motor.....

If it doesn't, is this auto temp or a manual system?

Remove the harness from the blower motor, and attach a test light to the two contacts in the harness.....with the heater system turned on, vary the blower speed from lo to hi......does the test light, light, and does it get progressively brighter?

If it does, bad blower motor....also check the contacts in the harness connector and in the blower housing....see if they are burnt and if any plastic surrounding the contacts have melted...

If the test light didn't light, you have to check each leg of the harness......ground your test light, and probe the colored wired(usually purple or red) circuit for power....if you have power, then the other circuit(your ground circuit, black wire), is open....