how to intermittent wipers muscle cars

I have noticed a lot of people on various forums asking how to get intermittent wipers on the old one or two speed classic and muscle cars. There are a few intermittent controls available on the market, but the problem is that many of the older cars controlled the wiper motor through the ground, and it is not a straightforward wiring job. So I thought I would put this post up, and invite some discussion.

See the link for the article - http://www.nthtechnologies.com/Cars/Wipers.htm

Thanks

How would you get multiple wipes doing that? I could see maybe with two 528's, but without a park switch on the motor, I don't see a way to retrigger the timer for more than one sweep.

Actually, with the old style (read: Muscle car era) GM cars, the internal park switch has its own internal ground. You have to disconnect the low and high speed terminals from ground (switch), but leave them jumpered to each other for the motor to park.

The 2-speed motor operates in low speed when the high and low terminals are connected to each other and ground, in high speed when the high speed terminal is connected only to ground, and it parks when the ground is disconnected, but the high and low terminals are connected to each other. The original switch is wired to do this.

I actually have a newer style wiper switch that has the washer and intermittent wiper controls built in to it. It has a billet knob and looks perfect in my car. I can get it to run my motor fine for the low/high speed wipes, but the problem is that it expects a signal back from the parking switch in the motor once every revolution, so it knows when to shut off. So if you set the switch to intermittent, it just keeps going in low. The real problem is that if you push the handle for the washer function, it is set to give 3 wipes, so it will never shut off (even if you turn it off), since my motor has no park terminal to send a signal. All I would really need are 3 + pulses 1/2 second long, with a 1/2 second pause in between, triggered when the low speed wire from the switch gets power.

The motor has an internal contact that maintains ground after the ground is removed by the switch.  This connection is broken mechanically once per revolution so the motor will stop at the correct park position.

If you look in my first post, there is a link to a schematic.  I am not sure how you would use that to generate a signal.