Re: Wiper Motor Test
Hi OP and ST, Move your wiper manually, just enough to determine its free and not bearing-seized. If seized, you may want to remove the unit anyway. Take it to the bench, they are somewhat simple..remove the two bolts and as you slide the case off have a couple of toothpicks to place into each of the two brush-holders through a small hole while pressing the brush into the holder. Do this for the two and you wont have brushes and springs rolling all about.
Now, check all wires to, through and attached to the motor for ware and breakage. Replace as needed, most brushes require a soldered joint while others are soldered-clips. With an ohm meter check the stator for shorts. (This test is relatively simple and YouTube probably has a stator test video illustrating how to).
The motor has two bearings, one on each end. check to see if bearings are turning freely. Check the motor stator ends for extreme wear
as well as marks grooved into the stator shaft from seized bearings. If OK, using a very-fine grit diamond sand paper sand the stator end shaft (part that gos into bearing) clockwise and not up and down. use a magnet to clear out magnetic particles and then use a solvent cloth twisted at end and clean-out the little slots on the stator. A little dab of white lithium grease at both bearing inner races.
2: unscrew the worm drive plate as you have bearing in there too and it's probably the one giving the most trouble. Pull out the round plastic geared sprocket to access the main bearing, soak the bearing and housing in gunk-out solvent for 24hrs warm. Using your fine sand paper clean the race inside the bearing-smooth as well as the sprocket shaft stud where it contacts the bearing. Dry all well with a hair dryer, grease the bearing and race, the sprocket teeth and stud then re-assemble.
If the project becomes to much, well you’ve learned something about motors..toss or trade-in for another. Your local auto-wrecker will probably have what you need at a far more reasonable price that buying a new motor. Before you buy or reinstall check all your wiring at the install point for corrosion and change where necessary. If your good with splicing you can cut off the the corroded part of the wire, usually a foot back and solder-in or using quality crimp barrel connector, crimp-in a new length. Good Luck.
