3 speed windshield wiper switch

[troublemaker]

Gentlemen any info will be greatly appreciated. I’m changing over from a 2 speed wiper to 3 speed. This is on a 70 Road Runner. The motor is installed and wires in. I unplugged the 2 speed switch and plugged the connector on my 3 speed switch and turned them on just to see what would happen. Of course it didn’t work. Now I know I have some terminals that are not being used, looking at photos it looks like one goes to a post ground for the dash. I grounded the switch ( I was holding it in my hand) and the wipers worked, but not well. The switch was heating up. Probably still a ground. Does anyone know If they make a jumper conversion to go from 2 to 3 speed. I’m going to start going through my wiring diagrams, thought someone might have gone through the same thing.

 

[PurpleBeeper]

I'm not much help since my car came 3spd, but I'd suggest just a careful look at the wiring diagram and see if you can add in the extra wires you need (I'm betting this is possible).

 

[threewood]

The wiring for the 3 speed should be on the harness already.

 

[troublemaker]

Threewood, excellent diagram. Pulled out my harness diagrams and figured it out, GREAT to see I was right when comparing to your picture diagram. Thanks a bunch. Grounded it and works fine

 

[lyndondb]

Threewood, excellent diagram. Pulled out my harness diagrams and figured it out, GREAT to see I was right when comparing to your picture diagram. Thanks a bunch. Grounded it and works fine

Not relative to your wiring question; but do you realize you will have to change your arms?

 

[troublemaker]

I did not know that, they seem to work fine. Travel of the wipers cover the whole window and they park on the bottom as they should. Something I don’t see? ( no pun intended)

 

[rakort]

Not relative to your wiring question; but do you realize you will have to change your arms?

Is it the arms/linkage/transmission that needs to be changed? I thought the arms and all that business was the same, but what is different is the crank that mounts on the motor output shaft that is different between the 2 and 3 speed varieties.

 

[lyndondb]

Is it the arms/linkage/transmission that needs to be changed? I thought the arms and all that business was the same, but what is different is the crank that mounts on the motor output shaft that is different between the 2 and 3 speed varieties.

The linkage/transmission arms are different