High speed blower relay
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High speed blower relay
Can anyone tell me the purpose of the high speed blower relay? My HVAC is working but after running fan on high setting for about an hour, it seems to slow down. If I stop and turn off ignition and then restart, it works again. After it slows it doesn't matter which selection is on ( max AC, norm, vent, heater, defrost)
I am thinking my relay might be failing.....
Appreciate any thoughts.
I am thinking my relay might be failing.....
Appreciate any thoughts.
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Joined: Mar 2016
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Ground appears good. It keeps going, just slow on all speeds after an hour. Then turn car off , restart and good for another hour at high speed.
Last edited by 80L48; Apr 17, 2016 at 08:36 PM. Reason: Spelling
Former Vendor
Joined: Aug 2006
Posts: 76,656
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
It may be that the motor is just on its last leg. The blower speed is controlled by resistance created by the resistor in the a/c housing. The resistance is determined by the position of the blower switch inside the car as show in the diagram below. The only thing that'll slow the motor down would be a motor failure coming on or an issue with the resistor.
Run 12 volts to the motor direct from another source, it should run at high speed then and see if the issue persist. I'm thinking that the blower is just getting worn out.
-Willcox
Run 12 volts to the motor direct from another source, it should run at high speed then and see if the issue persist. I'm thinking that the blower is just getting worn out.
-Willcox
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
You could jumper from the orange to the blower motor... bypass the purple completely. If the motor responds the same way I'd replace it.
Willcox
Willcox
Racer
Joined: Mar 2011
Posts: 480
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From: Los Angeles CA
It may be that the motor is just on its last leg. The blower speed is controlled by resistance created by the resistor in the a/c housing. The resistance is determined by the position of the blower switch inside the car as show in the diagram below. The only thing that'll slow the motor down would be a motor failure coming on or an issue with the resistor.
Run 12 volts to the motor direct from another source, it should run at high speed then and see if the issue persist. I'm thinking that the blower is just getting worn out.
-Willcox
[img]http://repairs.willcoxcorvette.com/wp-content/uploads/2015/07/1978-1982-corvette-heater-blower-
schematic.png[/img]
Run 12 volts to the motor direct from another source, it should run at high speed then and see if the issue persist. I'm thinking that the blower is just getting worn out.
-Willcox
[img]http://repairs.willcoxcorvette.com/wp-content/uploads/2015/07/1978-1982-corvette-heater-blower-
schematic.png[/img]
But before you spend your $$$ on a new motor. Add a extra ground. If that fails buy the motor.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
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Completed!
I just received and installed a new relay and the upgraded blower motor from Willcox. Works great now! Had to build the 3/4" spacer to accommodate the larger fan, but not too difficult. Thanks to all for the guidance.