the blower motor for the HVAC in my truck quit working. It stopped working for short periods a couple of times previously but this time it has been out for about a month this time. It does not work at any speed. Fuse #4 for ignition/blower is not blown.
I've removed the motor from under the dash and checked it for continuity with an ohmmeter. There isn't a short in the motor.When I check the voltage at the 2 wire terminal where the motor connects I read about 11.3 volts. this is true no mater what setting the fan speed dial is on or even if the 4 wire harness to the resistor is disconnected.I hooked the motor up directly to the battery with jumpers and it runs every time without fail.I removed the resistor and checked it for resistance with the ohmmeter...i'm not really sure in what combination to test the four different terminals but I got different readings with different combinations.
There is a small hairline crack in the resistor but I'm not sure this is a problem since I've read that the fan should work on highest speed even if the resistor is faulty.I just can't figure out why the motor runs when connected to the battery but not when connected to the terminals....even though I am measuring voltage at the terminals. It's not a bad connection from the terminals to the motor because I've used jumpers to test this theory. Is the motor not getting enough voltage from the terminals? Is the resistor bad? Help!!! It's getting cold in the mornings this time of year!
I've removed the motor from under the dash and checked it for continuity with an ohmmeter. There isn't a short in the motor.When I check the voltage at the 2 wire terminal where the motor connects I read about 11.3 volts. this is true no mater what setting the fan speed dial is on or even if the 4 wire harness to the resistor is disconnected.I hooked the motor up directly to the battery with jumpers and it runs every time without fail.I removed the resistor and checked it for resistance with the ohmmeter...i'm not really sure in what combination to test the four different terminals but I got different readings with different combinations.
There is a small hairline crack in the resistor but I'm not sure this is a problem since I've read that the fan should work on highest speed even if the resistor is faulty.I just can't figure out why the motor runs when connected to the battery but not when connected to the terminals....even though I am measuring voltage at the terminals. It's not a bad connection from the terminals to the motor because I've used jumpers to test this theory. Is the motor not getting enough voltage from the terminals? Is the resistor bad? Help!!! It's getting cold in the mornings this time of year!
Sep 29, 2010 at 3:19 PM