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Discussion Starter · #1 ·
On my blower motor for the heater, the resistor has three prongs on it. Two are parallel to one another and the other is perpindicular (sp?) to the other two. Which is which? I want to hook up a toggle switch to turn the blower on and off. Does one of these prongs need to be grounded? Or is the blower motor grounded to the frame?

I've tried jumping a hot wire to each terminal, but nothing happens. Do two of them need to be energized at the same time?

At what points do I need to check the windings for an open circuit?

Does anyone know the correct spelling for "perpendicular"? The spell checker shows it as a misspelled word, but offers no correct spelling.

Thanks.

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My Elky Page Updated 7-21-00
"Think for yourself. Don't let popular opinion make your decisions for you."
Chad Landry
TC Member #643
'68 El Camino
 

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Chad,
Two of those terminals represent each end of the resistor. The other terminal is the "center tap". In other words, the entire resistor is in series with the motor when in the "low" setting. When in the "medium" setting, only half the resistor is used, utilizing the tap. In the "high" position, the entire resistor is jumped out of the circuit by the blower switch, or, if you have a/c, by a relay, supplying a full 12 volts to the blower motor. DO NOT ground the terminals on the resistor. With a voltmeter check to see if you have 12 volts on all three terminals, when it is plugged into the harness and the blower switch is on.
If not, suspect a bad fuse or switch. If you do, suspect a bad blower motor or connection to the motor or a bad ground connection AT the blower motor. If you take the resistor out, you can see how it's constructed..actually two "wire wound" resistors in series. Where they are connected together is the center tap. If you tried connecting 12 volts to each of the connections and the blower didn't run, leads me to believe that your motor took a hike. See if you can get to the blower motor feed wire on the firewall side. Hook 12 volts up there and see what happens. If the motor runs, then you have a harness problem, if not, motor is probably toast. Good luck!


MalibuJerry350
Original owner '70 Chevelle.
540,000+ miles on car.
My Chevelle: http://hometown.aol.com/erie614/myhomepage/index.html

[This message has been edited by MalibuJerry350 (edited 12-07-2000).]
 

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Discussion Starter · #3 ·
Thanks Jerry. After posting this I thought about it some more and realized how stupid I was. I had it in my mind that the resistor was somehow wired to the motor inside the heater box. Then, while driving to my sister's house, I realized that I had completely eliminated the wire that leads from the resistor to the motor when I yanked my harness in the spring. I only made enough harness to replace "critical systems", which didn't include the blower at the time. Now with winter here the windshield gets a bit fogged at times and I definitely need the blower to deal with that.

I thought I'd come back to find someone asking, "You call yourself an electrician?"


Sometimes the simplest things elude me. Give me something complex every time.


Thanks for the help.
 
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