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Discussion Starter · #1 ·
The single-speed wiper motor in my just-bought'65 Mustang won't return to the parked position when it is turned off. We took it out and tried to get it to work on the bench, but it won't return to the "stop" or parked position there either. We borrowed a motor from another '65 that was out of the car but it won't return to stop either! Do we have two bad motors, or is there a trick to bench testing these? Can't figure out from the wiring diagrams if the stop return cycle is controlled by a hot wire or ground. Thanks, Ron
 

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Midlife walked me through it a couple years ago, IIRC the instructions were in the factory repair manual as well
 

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I did? I've never really paid attention to the wiper motors, as mine have always worked.

You need to consult the Electrical Assembly Manual and the Ford Shop Manual, would be my guess.
 

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I believe that in order to get the wiper motor to stop there needs to be a drag on the motor in order for it to slow down and come to a stop. The wiper blades making contact with the windshild provides the drag. Without drag the inertia of the motor makes the unit overrun the stop position. Try to hold the end of the motor when you switch it to the off postion and see if that works. I assume you are bench test by supplying power through the stock wiper switch with all wires connected because you have two hot wires going into the moter. One runs the motor and the other will power the motor until it comes to the stop position when the other wire's power is turned off.
 

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There are 2 power wires that go to the motor. One is a switched source, and that's what turns the motor on. The other wire is a constant power source and runs the motor after the switch source is turned off.

There is a set of points and a cam inside the motor. As the wipers pass the "parked position", the cam opens the points. So what happens when the wipers are turned off, power is removed from the switched source, but they're still being powered by the constant source up until those points open and break the circuit, thus stopping them. The switched source is really only used to power them when the points are open.

If they won't park by themselves, the cam inside is FUBAR. There's a bushing in there that wears out, making the cam not work right. I've had good luck in making a new bushing and making it work correctly again, but you have to disassemble most of the motor to get to it.
 

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Cruzzar said:
I believe that in order to get the wiper motor to stop there needs to be a drag on the motor in order for it to slow down and come to a stop. The wiper blades making contact with the windshild provides the drag. Without drag the inertia of the motor makes the unit overrun the stop position. Try to hold the end of the motor when you switch it to the off postion and see if that works. I assume you are bench test by supplying power through the stock wiper switch with all wires connected because you have two hot wires going into the moter. One runs the motor and the other will power the motor until it comes to the stop position when the other wire's power is turned off.
The wipers don't slow down and they don't need a drag on them. Following these instructions will only result in breaking something.
 

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johnpro said:
midpack said:
Midlife walked me through it a couple years ago, IIRC the instructions were in the factory repair manual as well

Psst ... that was me ;)
OMG, sorry :eek:
Sux gettin' old.....
 

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Discussion Starter · #9 ·
Great information everyone! Many thanks. I'm looking at a new (rebuilt?) motor from NPD. Ron
 
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