How to test a 3 speed wiper motor?

[resq302]

Does anyone know how to test a 3 speed variable wiper motor?  My dads wiper motor on his 70 chally vert that he just got is not working and there is power going out to the wiper harness and continuity from the plug to the splice points on the wiper motor wiring.  I would like to test the wiper motor to be sure that it actually works before I send it out and have it redone only to have it be in working order and get charged the $260 for the rebuild.

Thanks,

Brian

[kab69440]

Before you do anything else to it, rub a small bare spot on the housing and another on the cowl. Turn it on and ground it manually with a test probe. Most likely, the only thing wrong with it is a dirty ground. I spent a week trying to fix the wiper motor in my old Power Wagon. The second thing I SHOULD have checked, I didn't. I was so frustrated and once I found the real problem I felt like a complete dolt for not seeing it right off the bat. I hope this saves you that humbling...

[resq302]

When I removed the wiper motor from the firewall,  the brass ground strap was broken.  I made up a new one and sanded the area where the flat head screw goes onto the motor that connects the brass strap so it was good and bare.  Still nothing.  There were two wires at the bulk head connector that went to the wiring for the wiper motor that had power, a red wire and a brown wire.  When checked with a test light, the red wire had a nice and bright light and the brown wire had a light that was not as bright as the red wire.  That was with the wiper switch in the on position also.  I am thinking about pulling the wiper motor  barrel off and see if the brushes are toast or if the inside of the motor is just rusty or dirty.  The car has 141 K miles on it so it is possible that the wiper motor brushes are totally gone.  Nice thing is that the wiper motor is part number and date code correct just like everything else on the car.

[Back N Black]

Here you go.

Bench testing procedure.


Test #1(Hi speed)


Connect jumper wire from motor case to battery ground.
Connect second jumper wire from battery positive to BROWN lead.
Motor should run hi speed continuously.


Test #2 (Lo speed)


Connect jumper wire from motor case to battery ground.
Connect jumper wire from GREEN wire to battery ground.
Join BROWN and RED wires together and connect a jumper wire from battery positive to them.
Motor should run at slower speed.


Test #3 (Park)


Connect jumper wire from motor case to battery ground.
Connect jumper lead from GREEN to BROWN wire.
Connect jumper wire from red wire to ground.
Connect jumper wire from Blue wire to battery positive.
Motor should reverse and park.


(Depending on where the motor had stopped the park feature may have a full rotation or very short rotation

[resq302]

Back,

Thanks so much for that test procedure!     Now I just need to get to dads house to test it.  Hopefuly you saved him some money so he can get the other much needed parts for it.