Need help with 73 duster heater fan problems

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cudacrazy67

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I have a. 73 duster, ac car but not hooked up. My heater fan switch does not work unless I take the resistor out and put the coils together on the resistor. This tells me that something is messed up back through the system. Could it be a bad fan switch or something else. I think the fan switch is the only thing between the fan motor and resistor.
 
Just pulled and installed the whole dash structure. I had the dash harness out all together to paint my structure. I tried another resistor with same results.
 
The resistor is between the switch and the motor.
What do you mean by "put the coils together" ?
 
The two coils on the resistor must touch each other or his fan wont blow unless you hot wire it.
 
You should be able to visually see how the resistor is wired. That is, just take it out and look at it. If it doesn't have continuity between the terminals, at least part of the resistor is open

If you can SEE that the coils are broken apart, this is analogous to a burned out lamp filament
 
You should be able to jumper across the resistor terminals at the harness connector, and if the switch / harness is good, it should run "on high" at all settings of the switch. If it does, it's a resistor issue. If not, a harness / switch issue.

Are you sure it's not a MOTOR problem? If the motor bearings or blower wheel is dragging, it won't (might not) run on the lower speeds.
 
I will have to try a jumper wire. Witch prongs do I jump? I got 1 prong on the left and 3 prongs on the right. What prong on the right side do I jump to the left?
 
I can now swear it, but I believe 72--73 are the same. I don't have access to a 73, but you can download the 72 manual here. 74 saw many changes. The posted diagram is 72. This is page 24-52 from the AC / heater section of the manual

Actually, you don't NEED a diagram.

1...Just move the switch to high, key on, and verify that it works properly in high

2...Move the switch to medium, and probe the connector for power. Only one cavity will have power. Run a jumper from that cavity to the other two, and one of them should cause the motor to run......again.....on high.

3...Same thing for slow

If your wiring is same as below, jumpering light green to dark green should give you medium

jumpering black to dark green should give you fan in low

I've going here by the switch side of the connector because it's easier to see.

http://www.forabodiesonly.com/mopar/showthread.php?p=1970088617
 

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