Wiper Motor Failure

[Tbaumer]

Recently replaced my wiper switch with new, but the new switch does not get my wipers to work. When the old switch fell apart upon removal I thought that was the problem for sure, but no such luck. Here's where I am so far...
Harness plug to the wiper motor (with key turned on) has power to the green wire & gets power to the other wires as I change the switch.
Pulling the wiper motor wires off the motor plug box reveals continuity between the blue & yellow wires. Red has no continuity through the wiper motor to either.
Running direct 12 volt power to the motor yellow wire (which coincides with the blue/light green wire on the diagram - at the harness to motor plug box) or power to the red wire (that has no continuity to anything) does nothing. I've checked the wiper motor ground wire (blue) & it is connected to the bulkhead with continuity through the black wire to the bulkhead, so I believe I am left with a bad wiper motor. Am I missing something?

Then I looked at what it takes to remove & refurbish the wiper assembly on a LHD .

Can I disconnect the motor from the rest of the assembly in place without removing the entire assembly?

 

[expanse]

Can I disconnect the motor from the rest of the assembly in place without removing the entire assembly?

Yes. Pull wiper arms off, pull rubber boot (img_1084.jpg) up and unscrew (17mm?) the motor from the tube. pull motor & wire out. you'll have to change over bits from old to new motor. add a dab of lube to the wire when reassembling in reverse.

 

[Tbaumer]

You make it sound so easy! I'll let you know how it goes.

 

[MountainD]

It isn’t hard. However, the motor may be fine and stuck in a dead spot of the winding as well. Like what happens to Starter motors. So check that too. I’d also replace your park switch if you’ve had any issues with that. It’s only a tricky job to replace with AC…just more of a PITA. Sometimes, with motor switch on, you can manually try and advance a wiper to get it unstuck. It happened to me once so I know it can happen. I may have a spare motor from my other bulkhead if you can’t find one.

 

[UnfrozenCaveman]

My wipers didn't run when I got the '88.

Volt meter showed power at the motor.

Notice that it was a bit warm-ish.

Treated with percussive maintenance and it still runs 5 year later

Good Luck!

 

[Tbaumer]

Found some time to pull the motor. Not so hard after all - pushed the rubber boot up, removed the nut at the top. pulled harness plug & removed the clamp around the motor, so I could turn it around & take the back plate off, removed the circlip & slid the top of the cable out.

 

[Tbaumer]

Then I took it apart (since I'm replacing it anyway) & found everything in working condition - tested continuity, brushes a bit worn, rotor windings good, etc. Then reassembled & made some wires with connectors to bench test with a spare battery.

 

[Tbaumer]

Wouldn't you know it - It works! But only when going directly to the motor speed wires & bypassing the park switch terminals. Ugh, Way to turn an easy fix into a "pull my steering column/dash apart" mess. Ordered a new park switch (520160) & Brush Set (RTC198), just because the motor is already out.

 

[erover82]

Ugh, Way to turn an easy fix into a "pull my steering column/dash apart" mess.

I’ve got a pristine genuine LHD bulkhead for you when the shipfitters sets in.

 

[Tbaumer]

Replaced the park switch & brush set. Ran fine on the bench, so I installed it & tested in place. It tried to go then stopped. Removed the old motor & bench tested again - there is a "hitch" in the action after a few rotations. Figured there is too much resistance while connected in place with the wiper cable & the lack of smooth rotation. Ordered a new motor assembly.
Changed over the guts from the old motor to the new, installed & it works like a champ!



Then I realized that the screw at the end of the drive shaft on the old motor, that I removed when trouble shooting on the bench, was not re-installed (it is loosely in place in the pics below) allowing the motor rotor drive shaft to move in & out, causing the "hitch" I was seeing & likely binding the motor. Ugh. Looks like my old motor with the new brushes & park switch may have been good after all.