running wiper motor on the bench

[TimK]

My wiper motor is not running. I'm not sure how to hook up wires to test it. I tried running negative wire to one of the two hot terminals and positive wire to ground and got nothing. There are two "hot" terminals do both have to be connected to hot (negative). There apparently is a thermal breaker that may have gone bad when the motor overloaded the circuit and blew a fuse. Is that a replaceable item?

 

[GregW]

Hi Tim,
There are actually two grounds. The green is hot. The green/ black wire and the black are both grounds. There is an interrupt of the ground (black wire) in the disk area of the wiper assembly which allows it to park. The green/black wire (from the switch) bypasses the interrupted ground and allows the motor to continue spinning. So on the bench, you'd need to hook up the black and green/black to + and the green to -. (actually, on the bench the motor doesn't care what the polarity is, but the black and green/black are still hooked together.)

 

[TimK]

When I connected the negative to one of the terminals, my test light went on when I connected it to the other terminal and the positive terminal of the battery. Does that indicate a short across the negative and the overriding ground from the switch. If so, that would explain why the fuse blew. Can you identify which of the two terminal is which. My wires were covered in cloth and I could not tell which was green and which was green/black. I know where the black ground goes -- directly into the motor body.

Thanks for your info!

 

[GregW]

Hi Tim,
I just read 10 ohm across those two terminals so ours are both either OK or not. Not much help I know, but I've never had to troubleshoot one of these things. The wiring diagram says the Green/black (from switch) wire goes to the #1 terminal on the motor.

 

[TimK]

I have worked on the wiper motor and found that using positive terminal as ground and negative as "power", the circuit works when postive is attached to terminal #1 and to E (earth) and negative is attached to terminal #2.