1978 Chevy Silverado Blower motor runs with key on and ac c

1978 CHEVROLET SILVERADO
110,231 MILES • V8 • 2WD • AUTOMATIC
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FORSALEFORSALE1
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I have a 1978 silverado when the key is tuned on the blower runs constantly.A blue wire on the blower relay has 12 volt even when the switch is on.The purple wire to the blower has power with the key on.the red feed wire for the relay has a battery 12 volt constant.The realay is grounded through the body.I have read this is normal on that year is this true or do i have a bad fan switch.Any help is appreciated. Regards Jim
Sep 8, 2010 at 6:20 PM
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WRENCHTECH
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The motor is supposed to be powered all the time. The on/off and speeds are controlled by the ground side through the resister by the switch.

Try unplugging the resister, near the motor and see if it stops then. If it does, change the resister. If not, it's probably the switch.
Sep 8, 2010 at 6:40 PM
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