Blower motor crazy?
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Joined: Oct 2004
Posts: 78
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From: PA
Blower motor crazy?
Driving this afternoon the ac blower started acting crazy, it is blowing on and off for no reason. Sometimes it shuts off completely and sometimes the speed goes up and down. Nothing loose with wireing that I can see. Could make it change speeds while sitting in gear tapping on the gas pedal. Any ideas? 93 Coupe LT1
Team Owner
Joined: Mar 2001
Posts: 54,124
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From: Cincinnati, Oh USA
The blower motor is a d.c. motor with brushes and most likely the brushes are worn out and barely making connection to the commutator causing the motor to run intermittently. Bumping the accelerator causes the car to shake and the motor too which bumps the brushes into contact with the commutator. Unplug the motor and connect 12v to it and see if the motor will run continuously or intermittently. If intermittent, replace the motor. You can buy replacement motor at any auto parts store. If motor runs continuously, then you likely have a poor connection to the motor or the speed control for the motor is defective.
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Joined: Sep 2009
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The blower motor in my '98 Grand Prix has had a mind of its own for years. I took it out and cleaned it up, had some corrosion from a leak. It always works when I turn it on but it randomly blows air into the car any time it wants. I blamed the climate control but it seems to work otherwise. Maybe its a GM gremlin.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
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From: Australia
Advanced
Joined: Sep 2009
Posts: 80
Likes: 0
The blower motor in my '98 Grand Prix has had a mind of its own for years. I took it out and cleaned it up, had some corrosion from a leak. It always works when I turn it on but it randomly blows air into the car any time it wants. I blamed the climate control but it seems to work otherwise. Maybe its a GM gremlin.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
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From: San Diego, Ca
What everyone else says - but these Blowers can suck a lot of amps as they age and the harness terminals are crimped to the power supply - so make sure there isn't a loose connection that's opening/closing or dropping volts. Usually you'll see discoloration on the power wire and the weatherpak will have to come apart to solder up a decent connection. Try wriggling the connector/wiring around and holding it on the Blower Motor first. If it corrects the problem you'll know what to fix.
