two speed wipers. no washers

[Tom Tarlazzi]

I have a 64 chevy c10. replaced the original wiper motor with a two speed.
the motor has 4 connection points. I'm using a 2 speed switch with washer, which I plan on adding later.The motor doesn't have a washer on it. How do I wire this setup dor two speeds.

[ray_mcavoy]

Here's a pic of a typical 2 speed wiper motor with the terminals labeled according to the GM service manuals:



To wire up one of these motors:

Run a fused +12V feed to the #2 "power" terminal. This can be the feed wire from the old single speed motor.

Connect the #1 "high" terminal directly to the "high" terminal on the wiper switch.

Connect the #3 "low" terminal directly to the "low" terminal on the wiper switch.


I don't have a labeled pic of a wiper switch showing the terminals, but they're fairly easy to figure out using an ohmmeter / continuity tester.

In the off position, the switch should have continuity between the "low" and "high" terminals. But no connection from any terminals to the case (ground).

In the low position, there will still be continuity between the "low" and "high" terminals but they should also be connected to ground (switch case).

In the high position, only the "high" terminal should be connected to ground (switch case).

The remaining terminal will be for the washer and that one should only be connected to ground (switch case) with the button pressed.

To wire up the washer, run a short jumper wire from the motor's #4 "power" terminal over to one of the "washer" terminals (doesn't matter which one). Then wire the other "washer" terminal directly to the "washer" terminal on the switch.

Note that the metal case of the wiper switch needs to be grounded. That's usually accomplished by simply mounting the switch to the dash bezel. But paint, powder coating, etc. can sometimes prevent it from making a good contact.

Also note that the metal case of the wiper motor also needs to be grounded in order for the parking feature to work. Since the motor is mounted on rubber isolation grommets, there is usually a copper/brass strap that jumpers across a grommet to one of the mounting screws.