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07-25-2010, 06:09 PM | #1 |
The Older Generation
Join Date: Aug 2006
Location: Montezuma, Iowa
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Testing Windshield Wiper Motors
I am posting this in a new thread so it can be added to the FAQ section. It is instructions for testing the wiper motor out of the vehicle. I made up some jumper wires with spade terminals and/or alligator clips to make the hookups easier. Watch out for the rotating arm when you make the connections, it can wind the wires up pretty quickly...... The 2 speed wipers for the '67-'72 trucks are about half way down.
-------------------------------------------------------- Article from Ray’s Chevy Restoration Site http://rmcavoy.freeshell.org/electrical.html Q - How is the windshield wiper motor wired ? How can the circuit be tested ? A - Single speed wipers were base equipment on most early 60's GM vehicles. They have one (fused) power wire that is connected directly to the wiper motor. This wire is live whenever the ignition switch is on. A second wire connects the motor to the switch on the dash. When the wiper switch is turned on, it completes the circuit to ground (the dash). The single speed motor can be tested using the following procedure: * Use a test light (or voltmeter) to check for power at the wiper motor. Do this with the ignition switch on (wiper switch can be on or off). No power at the motor is an indication of a bad fuse and/or wiring. * Next, (with the ign switch still on) connect a jumper wire from the switch terminal on the motor to ground. That should cause the motor to run. If it doesn't then the motor is probably faulty. * Finally, the wiper switch can be tested with an ohmmeter or continuity tester. Also make sure that paint or corrosion isn't keeping the switch housing from properly grounding to the dash. Two speed wipers with washers were available as optional equipment on early 60's GM vehicles. They became standard equipment in 1965 or 1966. This system still uses the same basic wiring principles as the single speed wipers. There is still a power wire that feeds the wiper motor whenever the ignition switch is on. Except now there are three wires going to the switch. The switch grounds one wire for high speed operation. Two wires are grounded for low speed operation. The third wire grounds the washer solenoid to activate the washers. Note that many '75 and later vehicles used a small electric washer fluid pump mounted to the reservoir instead of the older wiper motor driven pump. 2-speed wiper motors - This is the '67-'72 wiper motor There are also 3 types of 2-speed wiper motors. One is a non-depressed park motor that is easily identified by its rectangular motor case. Another is a depressed park motor that has a round motor case attached to the gearbox at an angle. The third is a permanent magnet motor that has sort of a rounded 6-sided motor case. The diagram below illustrates the non-depressed park (rectangular case) motor. The washer has been omitted for clarity. The depressed park (round case) motor uses the same wiring concept except the terminals on the motor are arranged in a different order (3 Low, 2 Power, and 1 High). The permanent magnet motor (used primarily on 1978 & newer GM pick-up trucks) has separate terminals for the park switch and therefore uses a different wiring setup. 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. * Connect a jumper wire from a +12V source to the #2 (Power) terminal on the wiper motor. It's the bottom terminal on the rectangular motor or the middle terminal on the round motor. * Connect a jumper wire from ground to the #1 (High) terminal on the wiper motor. It's the middle terminal on the rectangular motor or the bottom terminal on the round motor. This should operate the motor at high speed. * Leaving the above connections in place, add an additional jumper wire between the #1 (High) and #3 (Low) terminal. #3 is the top terminal on both the rectangular and round motors. This should operate the motor at low speed. * On the rectangular case motor, leave the jumper between terminals #1 and #3 but disconnect it from ground. That should cause the motor to run (at low speed) until it reaches its park position at which point it should stop. * On the round case motor, leave terminal #3 grounded but unhook the ground jumper from terminal #1. 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. LockDoc
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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; 07-24-2020 at 08:22 AM. |
07-25-2010, 10:59 PM | #2 |
its all about the +6 inches
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Re: Testing Windshield Wiper Motors
outstanding! I have it in the electrical FAQ now.
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07-26-2010, 12:25 AM | #3 |
The Older Generation
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Re: Testing Windshield Wiper Motors
Thanks Andy...
LockDoc
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Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - |
07-26-2010, 03:08 PM | #4 |
Tot Roddin'
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Re: Testing Windshield Wiper Motors
Awesome writeup Leon!
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-Nate 1969 CST SWB - Project Blank Slate (4.5/6" ECE Static Drop, 6-lug disc brake upgrade (manual), Billet Specialties Vintec 20x8.5 255/40 (F) 20x10 295/40 (R), 250 I-6) 1960 AMF Skylark - Tot Roddin' (Lowered with custom frame; soon to include custom push bar and interior) 2008 Silverado CrewCab 1LT (5.3L, 3:73, 4x4, LT1, Z-71, Towing Package) |
07-26-2010, 03:33 PM | #5 |
6>8 Plugless........
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Re: Testing Windshield Wiper Motors
Nice job Leon!
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Ryan 1972 Chevy Longhorn K30 Cheyenne Super, 359 Inline 6 cylinder, Auto Trans, Tilt, Diesel Tach/Vach, Buckets, Rare Rear 4-link and air ride option Build Thread 1972 GMC Sierra Grande Longhorn 4x4 1972 Chevy Cheyenne Super K20 Long Step side tilt, tach, tow hooks, AC, 350 4 speed 1972 C10 Suburban Custom Deluxe 1969 Chevy milk truck 1971 Camaro RS 5.3 BTR STG3 Cam Super T10 1940 Ford 354 Hemi 46RH Ford 9" on air ride huge project Tired of spark plugs? Check this out. |
07-26-2010, 04:59 PM | #6 |
454 MAKES IT ROAR
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Re: Testing Windshield Wiper Motors
Thanks Leon, now I know why my wipers don't park themselves at the bottom of the windshield.
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11-13-2010, 12:22 AM | #7 |
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Re: Testing Windshield Wiper Motors
Thanks Leon, I have the same problem eightbanger had. Now I have something to work on tomorrow.
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11-13-2010, 12:56 AM | #8 |
The Older Generation
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Re: Testing Windshield Wiper Motors
-
Thanks guys. Glad it's helping out with the wiper problems... lockDoc
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Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - |
11-13-2010, 01:02 AM | #9 |
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Re: Testing Windshield Wiper Motors
Another master piece to add to the library. Great job and info.
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A husband can be right...or...A husband can be happy. 67-72 Chevy and GMC Trucks...The Classic Truck for the Classic Folk. 1970 CST Two tone green, 402BB, 400 Automatic, Tach, Buckets, AC, AM-FM, Tilt, GM CB, GM 8 Tract, LWB, etc JOHN 17:3...The better side of "LIFE" Remember: Everyday is a good day...Some are just gooder! |
11-13-2010, 01:30 AM | #10 |
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Re: Testing Windshield Wiper Motors
Glad to see this one going into the FAQs, I have been linking Rays website for quite a while.
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02-01-2011, 02:04 AM | #11 |
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Re: Testing Windshield Wiper Motors
Nice.
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03-04-2011, 05:40 PM | #12 |
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Re: Testing Windshield Wiper Motors
A very good and needed write up on testing the wiper motors (Thank you)
I have some additional information included on my build thread that might be of interest to you or others in troubleshooting their possible problems or wiring the system for a 67 – 72 Chevy truck (post #527) http://67-72chevytrucks.com/vboard/s...318544&page=22 I did barrowed the wiring drawing picture in your post to help clarify/understand my post better, hope you don’t mind and also created a link to your post in mine. Bruce
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My Build Thread: http://67-72chevytrucks.com/vboard/s...d.php?t=318544 |
03-05-2011, 12:17 AM | #13 | |
The Older Generation
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Re: Testing Windshield Wiper Motors
Quote:
LockDoc
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Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - |
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03-05-2011, 12:08 PM | #14 |
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Re: Testing Windshield Wiper Motors
Thanks this helps alot ,I'm in the middel of replacing the wireing harness in my 67 was not sure if the wiper motor even worked. I'm going to test mine right now.
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03-16-2011, 10:13 PM | #15 |
1 thing at a time is progress.
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Re: Testing Windshield Wiper Motors
Subscribing for future use. Nice work!!
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Alan
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03-18-2011, 10:09 AM | #16 |
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Re: Testing Windshield Wiper Motors
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- 1967 Chevrolet C/10 SWB fleetside (New Project). - 1969 Chevrolet C/10 SWB fleetside (SOLD) - 2000 Ford Mustang 232 (DD) - 2003 Ford SVT Cobra "Terminator" 281 (Once in a blue moon driver/weekend driver) |
03-18-2011, 10:53 AM | #17 |
Sisyphus was my mentor!
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Re: Testing Windshield Wiper Motors
Wiper motors have always been black magic to me. Thanks very much!
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03-18-2011, 06:30 PM | #18 |
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Re: Testing Windshield Wiper Motors
Finally got around to replacing the bad wiper motor, now we have working wipers that don't park on a new motor....
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03-18-2011, 11:56 PM | #19 | |
The Older Generation
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Re: Testing Windshield Wiper Motors
Quote:
Let me know what happens. LockDoc
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Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - |
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03-19-2011, 12:07 AM | #20 |
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Re: Testing Windshield Wiper Motors
Thanks Doc, will try tomorrow....
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03-23-2011, 07:50 PM | #21 |
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Re: Testing Windshield Wiper Motors
Tried to ground it with clips, still no park. I may pull the motor back out, scrape off any paint that may be the culprit.... who knows.... motor from Oreilly's might just have a bad park switch anyway.....
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03-23-2011, 10:06 PM | #22 |
The Older Generation
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Re: Testing Windshield Wiper Motors
-
I think One of the mounting bolt holes should have a brass washer with a strap that grounds to the wiper motor. LockDoc
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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; 03-23-2011 at 10:07 PM. |
09-14-2011, 06:22 PM | #23 |
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Re: Testing Windshield Wiper Motors
I have a question. On the two speed motor you show three terminals on the motor. Mine has 4 terminals. How do I test this motor?
EDIT: (See posts #66 & 67) Last edited by LockDoc; 03-05-2019 at 02:08 AM. Reason: Added Info |
09-15-2011, 12:32 AM | #24 | |
The Older Generation
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Re: Testing Windshield Wiper Motors
Quote:
LockDoc
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Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - |
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09-15-2011, 07:54 AM | #25 | |
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Re: Testing Windshield Wiper Motors
Quote:
Thanks for this useful thread and the help with the wipers!
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