Testing a Wiper Motor

[Hugh Heifer]

Been trying to find a working wiper motor to replace the one in my late '71 40.


The Max Ellery Manual says to do this to test the motor out of situ:

Has anyone tried this and had it work? I am beginning to doubt this as a proper procedure.

 

[missipboy]

i jumped wires from my battery to my unplugged wiper motor. it worked fine, so i started looking through the wiring harness for my problem.

 

[Fast Eddy]

Hey! I didn't see that ground wire going over to the mounting hole before. I don't remember seeing such an animal when I was testing mine. Hmmm...

 

[Hugh Heifer]

Thanks missiboy...and keep trying Eddy. I have two on the bench and both are giving me problems. I still want yours if you can get it to test.

 

[LCS]

Run the hot wire to #2 and ground to #4 for hi and then #3 for lo. If it just sparks then something is bound up. I'm rebuilding one right know and went to test the motor B4 installing the guts and it just sparked. Loosened up the screw that touches the end of the motor shaft and it worked perfectly.

 

[Fast Eddy]

Run the hot wire to #2 and ground to #4 for hi and then #3 for lo.

That goes against what it says in the printout above, but so does the test I did night-before-last. Mine did not appear to have an extra ground wire sticking out of it. The plug is a bit different than shown as well. I'll try your method. I got no sparks, nothing, leading me to think I wasn't grounding it.

 

[Hugh Heifer]

That goes against what it says in the printout above, but so does the test I did night-before-last. Mine did not appear to have an extra ground wire sticking out of it. The plug is a bit different than shown as well. I'll try your method. I got no sparks, nothing, leading me to think I wasn't grounding it.

Yeah. Same here on 2 othrs. Is this BS?

 

[fjwagon]

Yep, just remember that the casing is the ground.

Run the hot wire to #2 and ground to #4 for hi and then #3 for lo. If it just sparks then something is bound up. I'm rebuilding one right know and went to test the motor B4 installing the guts and it just sparked. Loosened up the screw that touches the end of the motor shaft and it worked perfectly.

 

[LCS]

Yep, just remember that the casing is the ground.

Normally the motor grounds itself, but in this testing procedure the ground is connected as described.

 

[Fast Eddy]

Normally the motor grounds itself, but in this testing procedure the ground is connected as described.

Yup. Mine works great. It's yours if you want it Hugh. It looks different than the diagram. I hope it's the right one. It has both spacers and I'll throw in the wiper arms which look mismatched to me, but they're close. Obviously the PO of this rig was running them. The plug has seen better days. The craptastic blue paint comes right off with a fingernail scratch.

 

[Hugh Heifer]

Yup. Mine works great. It's yours if you want it Hugh. It looks different than the diagram. I hope it's the right one. It has both spacers and I'll throw in the wiper arms which look mismatched to me, but they're close. Obviously the PO of this rig was running them. The plug has seen better days. The craptastic blue paint comes right off with a fingernail scratch.

Sold.
How did you finally do it?

 

[Fast Eddy]

Sold.
How did you finally do it?

Run the hot wire to #2 and ground to #4 for hi and then #3 for lo.

 

[Hugh Heifer]

Interestingly enough, I tried the test method above and it failed to function. Said to heck with it and put it in and yippee, I have working wipers. Additionally, I completed the rebuild of the one that I took out and thought I would try it too. Guess what - another success. Not sure why I can not get them to test on the bench but pleased with the success. :shrug:

I also have a third doner that I took some gears and splined shaft out of so plenty of spare parts now!

For future ref, here is something related:
https://forum.ih8mud.com/40-55-series-tech/190378-commutator-bar-shorts.html

 

[Degnol]

IIRC, mine is grounded with it's own ground wire in the 4-wire loom. Ground, low, high and self-park.


Ed