wiper motor doesnt work

Author Topic: wiper motor doesnt work  (Read 2132 times)

Offline Scat Pack Fever

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wiper motor doesnt work
« on: October 02, 2013 - 09:06:11 AM »
I installed my wiper motor, turn the key on, turn the switch and nothing happens. Not sure if its the wiper motor or something electrical, or the switch itself. Is there anyway to test the wiper motor outside the car? Does the motor need to be grounded to the firewall?




Offline Super Blue 72

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Re: wiper motor doesnt work
« Reply #1 on: October 02, 2013 - 09:26:10 AM »
Not sure if the wiper motor is grounded at the body, sorry not much experience with these wiper motors.

Make sure that there is power at the wiper motor, I assume at the red wire.  See the below pics for the schematics for the wiper motor and switch.  If there is power at the connector at the motor, may be someone can verify if the wiper motor is grounded at the case by the case itself or a metal tab/strap to body ground as it seems that there is no obvious black ground wire at the connector.




1972 Dodge Challenger Rallye 340, AT, Code TB3=Super Blue, SBD=8/17/1971.  Yes, a Rallye without the fender louvers from the factory because of the body side molding option.

Pic #2 and 3 of my ARII 1/24 scale model car 

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Offline mrwfp

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Re: wiper motor doesnt work
« Reply #2 on: October 02, 2013 - 09:49:59 PM »
Is it a 2 speed or a 3 speed wiper motor?  I have the bench test procedure for the 3 speed that lets you check it through the motor harness plug that goes into the firewall. That will let you know if it's the motor or the switch.  Here is the 3 speed procedure:

The harness from the motor to the firewall has 4 wires/prongs in it.  Blue, red, brown and green.

Disconnect motor leads at bulkhead disconnect (unplug the motor harness from the firewall connector).  Connect a jumper wire from the battery positive terminal to the brown and red leads in bulkhead disconnect plug. Connect a second jumper from the green lead to ground. The ground circuit is completed through the car body.  The motor should run continuously with power from the battery.

To check the park feature on a 3 speed motor:
Connect a jumper wire from the green lead to the brown lead in the bulkhead disconnect.  Connect the red lead to ground.  Connect a third jumper wire from the battery positive terminal to the blue lead.  The wiper motor should reverse and park. 

Ensure that all wires are connected correctly or else you could damage the motor.

Offline HP_Cuda

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Re: wiper motor doesnt work
« Reply #3 on: October 02, 2013 - 11:56:46 PM »

A quick test would be to add a ground wire from the back of the dash switch bezel to a good ground point.

Then test the wiper again.
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Offline rattlesnake

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Re: wiper motor doesnt work
« Reply #4 on: October 03, 2013 - 08:48:18 AM »
On my 70 the wiper motor is mounted with rubber bushings and there is a copper strap that runs from one of the mounting bolts to a screw on the top edge of the front face of the motor for grounding. Not sure about later years.

Ray,
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Offline JoeGrapes

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Re: wiper motor doesnt work
« Reply #5 on: October 04, 2013 - 10:14:35 AM »
I don't know if you replaced the wiper motor because you always had problems with it but mine used to work vary erratically. I never knew what was going to happen when I turned it on. When I had the dash apart over the summer I took the switch out and soaked it in alcohol while working the switch to clean it. After I put it back in it works great now. Not the motor at all but the switch.   

Offline burnt orange

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Re: wiper motor doesnt work
« Reply #6 on: October 04, 2013 - 10:53:08 AM »
On my 70 the wiper motor is mounted with rubber bushings and there is a copper strap that runs from one of the mounting bolts to a screw on the top edge of the front face of the motor for grounding. Not sure about later years.

Ray,


 :iagree:

Yup, I'll bet that ground strap needs attention.
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