Windshield washers

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steptoe
Posts: 9
Joined: Sun Nov 03, 2019 9:13 am
Location: Biloxi, Ms

Windshield washers

Post by steptoe »

Well I couldn’t get the washers to work on my ‘64 Monza so I took it apart and found no ground wire. Fixed that and reinstalled the assembly. Wipers and washers work great except the washers keep recycling on. They wash and stop like their supposed to but then restart again by themselves. What happened? Anybody familiar with this?

66vairguy
Posts: 2232
Joined: Tue Dec 21, 2010 3:44 pm

Re: Windshield washers

Post by 66vairguy »

Hmmmm - not sure what you mean by no ground wire. The wiper/washer unit only turns on when the WIPER SWITCH grounds the wiper motor or solenoid to activate the washer. There is a wiper motor ground via one of the wiper motor grommets that is ONLY used for the "park" function. When you turn off the wiper switch the motor would stop at any position - no good. The wiper motor keeps going until the wipers are "parked" at the base of the windshield using internal points that ground the motor UNTIL the wipers are at the park position, then the points open and IF the wiper switch is off (motor not grounded) the wiper motor stops.

The washer switch button also grounds the washer solenoid momentarily to engage a pawl to a cam and once the cam rotates it resests and what washer pump stops until the switch button is depressed again.

To summarize power goes to the wiper assembly and the wiper switch ONLY grounds the wiper motor or washer solenoid to activate them.

When the washer won't turn off it's either a stuck pawl on the cam (mechanical issue) or the solenoid is grounded all the time.

It seems odd the wiper switch only grounds the wiper/washer, but it's a clever way to make the wipers "park" and saved wiring.

steptoe
Posts: 9
Joined: Sun Nov 03, 2019 9:13 am
Location: Biloxi, Ms

Re: Windshield washers

Post by steptoe »

There was no ground wire but there was a broken metal tab which must have been an internal ground. I I installed a ground wire and the wipers now park as they should. The pump appears to be working normally. When it works, it cycles several pumps like it should and turns off. However, it immediately starts the cycle again. Over and over. The only way to stop this cycle is to unplug the wiring harness at the pump. Do I have a bad wiper/washer switch? Is the push button stuck?

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terribleted
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Location: Atlanta, GA
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Re: Windshield washers

Post by terribleted »

It could be the push button part of the wiper switch is stuck providing ground to run the washer unit all the time. More likely the washer unit has an issue with its holding points (stock) or mechanism (aftermarket) that is keeping the coil that turns on the pumping action energized all he time or perhaps something bent so that the pump arm is constantly in contact with the ratchet that runs it. I just fixed a brand new replacement pump that was doing the same thing as yours. It has a metal arm that catches little cogs on a gear to operate the pump. There was a disengage plunger that was working properly but even though it was pushing the arms away from the cogs the arm was still catching them. I bent the arm to provide clearance in the off position and now it works like a champ. The shop manual supplements show a nice photo and have diagnostic info for the washer pumps...check it out.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
Currently working full time repairing Corvairs and restoring old cars.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia

erco
Posts: 394
Joined: Wed Apr 29, 2020 8:45 pm

Re: Windshield washers

Post by erco »

Here's a "generic" GM wiring diagram for the wiper switch, which happens to be from a '65 Greenbrier. :) Sounds like a common problem is not having the wiper switch properly grounded to the metal dash.

From http://www.persh.org/Pickup/Wiper-washer.htm
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erco
Posts: 394
Joined: Wed Apr 29, 2020 8:45 pm

Re: Windshield washers

Post by erco »

OMG that washer pump mechanism is such a gorgeous caliope. Quite the Rube Goldberg design. Mine isn't working, I was about to slap on an aftermarket pump (probably the smartest move overall) but when I saw how it works, this engineer fell in love with that fabulous mechanism. Of course the half-century-old rubber bellows/diaphragm was shot.

And thus my search for parts began. A pity the diaphragm alone costs $22 shipped! Whoever tooled that part has certainly made his money over the years, many GM cars use it, including Camaros, Chevelles & Corvettes. Clark's doesn't even sell it anymore. https://www.ebay.com/itm/192832229093

That ebay seller also offers a complete kit for $32 shipped: https://www.ebay.com/itm/202859466285

Or pick up a repair kit with everything but the diaphragm from your LAPS: https://www.oreillyauto.com/detail/b/do ... 4000&pos=0 or https://www.autozone.com/electrical-and ... 8/343263_0 FYI, kits include 2 different tops where the hoses connect. Corvettes use the top with straight-out connectors, Corvair & Camaro use the top with perpendicular connectors.

Complete pumps are $50-60 most places, even $69 at Clark's. Outlier Autozone says they can get one for $22. We'll see, I ordered but they often can't get stuff on their own website. But if they can, that's the same price as the diaphragm alone so it's worth a shot. https://www.autozone.com/electrical-and ... 343262_0_0


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erco
Posts: 394
Joined: Wed Apr 29, 2020 8:45 pm

Re: Windshield washers

Post by erco »

Bummer. Autozone got the pump but it's not interchangeable. Looks close but the drive height is wrong and the electicals are different.

erco
Posts: 394
Joined: Wed Apr 29, 2020 8:45 pm

Re: Windshield washers

Post by erco »

Best price I found is just the pump diaphragm for $18, free ship (saves $4 shipping from the ebay link I posted previously):

https://www.csofmdwest.com/product/1963 ... p-bellows/

I'm ASSuming the pump repair kits from O'Reilly Autozone fit. Will advise.

66vairguy
Posts: 2232
Joined: Tue Dec 21, 2010 3:44 pm

Re: Windshield washers

Post by 66vairguy »

Nice work Erco - Hopefully the part will work. Looking forward to what you find.

erco
Posts: 394
Joined: Wed Apr 29, 2020 8:45 pm

Re: Windshield washers

Post by erco »

A look at the cool washer pump clockwork mechanism... while I await delivery of my pump bellows.

Windshield washer pump mechanism goes through one cycle here with the plastic dust cover removed. Linear motion comes from a rotating cruciform cam (hidden behind) driven by the wiper mechanism. A portion of the linear mechanism oscillates whenever the wipers are moving. When pressed, the dashboard pump switch momentarily grounds a solenoid connection and the coil attracts the lever at the bottom left, allowing the cycling pawl to ratchet advance the white gear from its HOME position, where a small projection was previously holding some electrical contacts open. Once the gear rotates slightly, the spring-loaded contacts snap closed. This makes a parallel ground connection for the solenoid, which thus remains energized even after the dashboard pump switch is released, until the gear makes a full revolution and the tang breaks the connection in the HOME position. Pumping action for washer fluid comes from a rubber bellows and check valves inside the upper black plastic housing occasionally seen here.


erco
Posts: 394
Joined: Wed Apr 29, 2020 8:45 pm

Re: Windshield washers

Post by erco »

Mission accomplished, my washer pump now works great using parts previously mentioned:

$6 Autozone pump repair kit: https://www.autozone.com/electrical-and ... 8/343263_0

$18 bellows/diaphragm: https://www.csofmdwest.com/product/1963 ... p-bellows/

R&R and repair is straightforward. Trickiest part is installing the new bellows/diaphragm under spring pressure and locking with 1/4 turn. Spring is pretty strong and getting everything aligned blind ain't easy. Photos attached.

You won't use all of the parts in the Autozone repair kit, it's a universal fit with several extra parts. Just the valve body plate, upper 90-degree fitting plate (both were black nylon in my kit) and the 3-ring rubber gasket. I reused my pump spring and all 4 pump body screws.

The cruciform drive cam behind the pump rotates clockwise. It's actually part of the motorized windshield wiper mechanism and does exactly one full turn (delivering 4 pumps) per wiper cycle. There are ~21 teeth on the internal gear wheel, so once energized, the pump solenoid will stay on (and fluid will squirt) for at least 5 full wiper cycles before the pump wheel homes and opens the contacts to turn off the solenoid coil.

That's the main thing I don't like about this design. If you turn off the wipers before the contacts open, the solenoid just stays on forever. Wastes power, heats up the coil with no indication that it's on. Current will flow through the coil whenever the accessories or ignition is on until you turn the wipers on again long enough for the pump to turn itself off. Boo! Hiss!

Two recommendations to extend the life of your washer pump:

1) Don't turn off the wipers until you see the washer pump stop squirting, and
2) Per others, never operate the pump dry. Without washer fluid acting as a damper, the spring-loaded diaphragm slams hard and that impact is bad for the mechanism.
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