# Wiper switch turns on backwards



## Red Skeleton (Jul 2, 2019)

My 68 Lemans' wiper switch turns on and off backwards. Clockwise is off. CC is on It's a 2 speed wiper. Used a wiring diagram and all wires check out. I even took a chance and flipped the 2 spade plug and it blew the fuse. It works fine except it's backwards. Is there a way to reverse the polarity in the motor itself? Thanks!:wink3:


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## O52 (Jan 27, 2019)

I'm assuming you have the optional (hidden) wipers and you have little experience as an electrician.

The wipers operate by grounding the Black and Black/Blue wires from the motor through the wiper switch which should be grounded. Make sure the ground strap behind the switch is grounded properly. Use an ohm-meter from the switch housing to a good carbody ground to verify.
Unless its defective, the wiper switch is hard to miss-wire but check the wiring (photo) anyway. Anything can happen in 51 years.

The 2 spade plug is for the washer pump. The Black/Yellow wire is the 12 volt source and jumpers to the #2 terminal of the motor. The Black/White wire goes to the switch and is the pump ground whenever the switch is pushed in.

If the wiper switch is grounded properly check the plugs (2) on the motor. Hard to see but they are to the lower right of the washer pump plug. 
The single wire plug (Black/Blue) should go to the right. The two wire plug is to the left. 
The two wire plug Black/Yellow wire (12 volts from the washer pump) should be to the right and the Black/White is to the left. See photo.

Photo of the wiper motor is from my El Camino and the wire colors are slightly different. Other photos are from my 68 GTO's harness (to be installed)


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## Red Skeleton (Jul 2, 2019)

Thanks VERY much 052.
Your wiper assembly is different than mine. I don't think these are the hidden type either I've checked the plug at the switch and it cannot be put on wrong. I have a schematic and the wire colors check out. In my mind, the only thing it could be is within the switch. Wild that it would be the opposite and have the 2 speeds work too(windshield pump doesn't)? I'll check the ground as you said but i don't see how these symptoms would be the result?

That switch isn't bad to get out and I'll open her up. I think my polarity idea was a dumb one.


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## Red Skeleton (Jul 2, 2019)

Also I think your grounding info is valuable because it might be plausible that it lost the ground at one end and gained it at the other?


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## PontiacJim (Dec 29, 2012)

Red Skeleton said:


> My 68 Lemans' wiper switch turns on and off backwards. Clockwise is off. CC is on It's a 2 speed wiper. Used a wiring diagram and all wires check out. I even took a chance and flipped the 2 spade plug and it blew the fuse. It works fine except it's backwards. Is there a way to reverse the polarity in the motor itself? Thanks!:wink3:



Read this and see if it is of any help: https://www.gtoforum.com/f12/`68-wiper-switch-55890/


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## O52 (Jan 27, 2019)

Check the back of your dash for the ground straps. See photos. For the grounding system to work properly the switches must be tight against the dash. The straps theirselves must be grounded to the metal dash supports. 
The wiper motor should also have a ground strap from the washer pump frame to one of the wiper mounting bolts.

The 68 diagnostic manual says to reverse harness leads one and three if the motor turns off in the high speed position IF THE GROUNDS ARE ALL CORRECT. See diagram for terminal board orientation. This is for the standard motor that you think you have. 

I don't have the dash installed in the car since its in the middle of a restoration but hopefully the photos will give you an idea of what should be there.


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## Red Skeleton (Jul 2, 2019)

Here's some photos of what I have. Please tell me you see wiring out of place, the switch WAS loose but I snugged it up. Haven't had a chance to look behind the dash yet. I discovered the washer tries to work when I push the button. I ran a ground wire to the wiper motor case-no change. Thanks for all of your help!


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## O52 (Jan 27, 2019)

From what I can see the wiring looks correct. Which leads me to believe you have a grounding problem. Need to stick your head under the dash and take a look 

Has it been this way since you owned the car or just happened?


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## Red Skeleton (Jul 2, 2019)

Since I've owned it, about 4 months ago


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## O52 (Jan 27, 2019)

I did a little more research (sales brochures, etc) and I think I see a problem with the pictures you sent.
Can you send a picture of the Fisher Body data plate? And the wipers with the hood open and closed.

You say you have a Lemans, and the wood dash would indicate that. But...
Lemans series had the disappearing wipers (the blades would hide below the hood when off) which had a different wiper motor than what you show. It looks like someone may have changed the motor in the past. 

But again the wiring didn't change between the two types of motors so it still should operate even though the motor is wrong. I still think you have a grounding problem.

Photo of the motor for disappearing wipers.


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## Red Skeleton (Jul 2, 2019)

Thanks 052,

It's a GTO clone. I thought the wood grain was added for a GTO? It also has a GTO hood if that matters?


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## PontiacJim (Dec 29, 2012)

Red Skeleton said:


> Thanks 052,
> 
> It's a GTO clone. I thought the wood grain was added for a GTO? It also has a GTO hood if that matters?



My '68 Lemans has the factory wood grain as well, so it was not added for the GTO look.


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## Red Skeleton (Jul 2, 2019)

Ah, good to know, Thanks Jim!


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## Red Skeleton (Jul 2, 2019)

O52 said:


> I did a little more research (sales brochures, etc) and I think I see a problem with the pictures you sent.
> Can you send a picture of the Fisher Body data plate? And the wipers with the hood open and closed.
> 
> You say you have a Lemans, and the wood dash would indicate that. But...
> ...


I opened up the wiper switch today but checked it before with an ohm meter from one copper spade that's by itself to switch case I DON"T get continuity in the full counterclockwise position (OFF position if it was working right). The first click CW AND the second click I DO get continuity to the case. On the second copper spade that's next to the washer spade that is silver in color, in the CC position I DO get continuity, and the second position I DO, and the full CW position I get NO continuity.

I don't understand how it works, but I took the switch apart and found nothing broken inside. The silver spade that operates the push button washer rivet was loose so I fixed that, cleaned her up and put her back together. Did all the continuity tests again and they're the SAME. I checked your pic of the switch plugged in and the wires are in the right positions. (very helpful)

I don't believe it's the switch. If as you said that the switch grounds the wiper to work, why would the switch be grounding one spade in the off position? (I think I'm out of my league here). Could you check you switch to see if they match? Thanks much






Just don't get it.:frown3:


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## O52 (Jan 27, 2019)

I figured it out. 

First the ground rules.

*Two different wiper systems for the GM A body cars from 68-72*

The first is the standard system which is primarily on the lower trim levels. (Tempest) This has the square wiper motor and single arm wiper blades.

The second is the optional wiper which is on the higher levels of trim (Lemans, GTO) and _optional on the lower trim levels_. It has the round motor and articulated wiper arms (two arms for the drivers side wiper.) These are also known as the _Hidden or Recessed Wipers_ since they drop below the hood when off. 

*There are also two different switches for the two types of motors.* 
When I was reviewing the wiper diagrams in the diagnostic manual I noticed that the switch contacts for the square motor were different than the round motor. I also noticed (by accident) that the two switches I have behaved differently in respect to which terminals were grounded when off or shorted to each other when in hi or low speeds. 

Now in your case you have a GTO clone but the model number on your Fisher Body plate says its a LeMans. It really doesn't matter since both have the hidden wipers. Sometime in the past someone replaced the round motor in your car with a square one. This created all sorts of problems as you have found out. 
First of all the wipers will not park properly when turned off, and secondly, the switch will not work correctly. 

So, you need the proper motor to make things right. Ames has the Tempest switch if you don't want to replace the motor.
And make sure the switch housing is polished around the housing where the grounding ring goes around it. I could not get a good reading until I cleaned the oxidation off with steel wool.

Until I thoroughly read the diagnostic manual I assumed the switches I had were the same. I had bought a spare years ago and just by chance it was for a Tempest, not a GTO. When I tested each switch the results corresponded to the diagrams in the manual for each type of motor. 
And I learned something new today.:nerd:


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## Red Skeleton (Jul 2, 2019)

O52 said:


> I figured it out.
> 
> First the ground rules.
> 
> ...


You are amazing, thank you! But don't you mean that the whole setup is needed meaning I need the motor AND the articulated arms arms if I want the hidden version?:surprise:


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## O52 (Jan 27, 2019)

You already have the articulated wire arms. Look at the drivers side wiper. You'll see a smaller arm attached to the large arm. The articulated arm keeps the blade vertical as it reaches the end of its sweep near the A pillar. 
What you may need is the adapter plate between the motor and the firewall. There is also a thick sponge type gasket that goes between the motor and adapter plate. 

Are you on the West Coast?


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## Red Skeleton (Jul 2, 2019)

Yes, Sonoma County. Ca. Yes I see the second arm on the drivers side wiper. Also I think you're right about the adaptor plate being needed. The hole the motor sticks through is oblong, not round like your picture.
I'm tight for $ right now and may go the switch route or just put up with the backwards switch. They'll never be a time when I drive the car in the rain as the front and back windows leak so that's priority.


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## O52 (Jan 27, 2019)

OK. Glad I could help and that I learned something too.


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## Red Skeleton (Jul 2, 2019)

Me too, thanks again. You're the best!


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## Red Skeleton (Jul 2, 2019)

O52 said:


> I figured it out.
> 
> First the ground rules.
> 
> ...


Hey Ed, just wanted to thank you again for your genius and help on solving this. It's been almost a year and I've ordered the correct wiper motor and it's on its way after re-reading your excellent explanation. Thank you!😁


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## Red Skeleton (Jul 2, 2019)

And for everyone else I've rebuilt and installed the new wiper motor and everything works as it should!


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## O52 (Jan 27, 2019)

Good to know. Thank you for updating the group.


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