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**LockDoc** · 04-30-2020, 04:35 PM

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OK, I told you wrong on the test. I knew I should have double checked before I posted that. I will delete my previous post and start over. I will post a condensed version of the instructions and a picture in the same post and maybe that will make it easier for both of us. The new picture has the terminals numbered to coinside with the instructions, see if that makes it easier. Remove all of your wires and start over....

Testing the wiper motor independent of the switch: (in or out of the vehicle)

The depressed park and non-depressed park 2-speed wiper motors can be bench tested independent of the dash switch by making the following connections:

* Ground the wiper motor housing. (to negative post on the battery)

* Connect a jumper wire from a +12V source (positive on the battery) to the #2 (Power) terminal on the wiper motor.

* Connect a jumper wire from ground (negative on the battery) to the #1 (High Speed) terminal on the wiper motor. This should operate the motor at high speed.

* Leaving the above connections in place, add an additional jumper wire between the #1 (High Speed) and #3 (Low Speed) terminals. This should operate the motor at low speed.

* Leave the jumper between terminals #1 and #3 but disconnect the motor from ground. That should cause the motor to run (at low speed) until it reaches its park position at which point it should stop.

If the motor operates normally in the above tests but not when installed on the vehicle then the problem is most likely in the switch or maybe the wiring. Also, the switch has to be grounded to the dash or the wiper will not work. Don't forget to check the fuse. The switch can be tested with an ohmmeter.

If the motor stops immediately when switched off (doesn't return to park position), first check the motor's ground strap. Since the motor is mounted on rubber cushions, it's grounded via a copper strap attached under one of the mounting screws. This is the ground for the park switch so the parking feature won't operate if the ground strap is missing, dirty, or corroded. If the ground strap checks out okay but the motor still doesn't go into park then the problem is most likely a worn out or dirty park switch. The park switch is located inside the motor's gearbox so some disassembly is required to check/clean the switch. I recommend consulting a good repair manual for the motor disassembly procedure.

See how that works.

LockDoc

04-30-2020, 04:35 PM	#141
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 25,331	Re: Testing Windshield Wiper Motors - OK, I told you wrong on the test. I knew I should have double checked before I posted that. I will delete my previous post and start over. I will post a condensed version of the instructions and a picture in the same post and maybe that will make it easier for both of us. The new picture has the terminals numbered to coinside with the instructions, see if that makes it easier. Remove all of your wires and start over.... Testing the wiper motor independent of the switch: (in or out of the vehicle) The depressed park and non-depressed park 2-speed wiper motors can be bench tested independent of the dash switch by making the following connections: * Ground the wiper motor housing. (to negative post on the battery) * Connect a jumper wire from a +12V source (positive on the battery) to the #2 (Power) terminal on the wiper motor. * Connect a jumper wire from ground (negative on the battery) to the #1 (High Speed) terminal on the wiper motor. This should operate the motor at high speed. * Leaving the above connections in place, add an additional jumper wire between the #1 (High Speed) and #3 (Low Speed) terminals. This should operate the motor at low speed. * Leave the jumper between terminals #1 and #3 but disconnect the motor from ground. That should cause the motor to run (at low speed) until it reaches its park position at which point it should stop. If the motor operates normally in the above tests but not when installed on the vehicle then the problem is most likely in the switch or maybe the wiring. Also, the switch has to be grounded to the dash or the wiper will not work. Don't forget to check the fuse. The switch can be tested with an ohmmeter. If the motor stops immediately when switched off (doesn't return to park position), first check the motor's ground strap. Since the motor is mounted on rubber cushions, it's grounded via a copper strap attached under one of the mounting screws. This is the ground for the park switch so the parking feature won't operate if the ground strap is missing, dirty, or corroded. If the ground strap checks out okay but the motor still doesn't go into park then the problem is most likely a worn out or dirty park switch. The park switch is located inside the motor's gearbox so some disassembly is required to check/clean the switch. I recommend consulting a good repair manual for the motor disassembly procedure. See how that works. LockDoc Attached Images __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - Last edited by LockDoc; 04-30-2020 at 10:42 PM.