I did a search and didn't see anyone having the same problem I am with my wipers. The car is a '67 with 3 terminal 2 speed wipers. The wipers worked before I ripped out the interior. I rewired the car and am now in the process of putting it back together. At first the wipers would only work if you pushed the switch in as if to activate the pump. I replaced the motor with a new unit. Plugged it up then the motor would run on the high speed no matter what position the switch was in even off, but they did slow down if I pushed the switch in to activate the pump like they are suppsoed to. I figured the switch was bad and replaced it and it does the same thing. Any idea what could be wrong? I have checked and rechecked my wires many times. I have a feeling that something is not grounding properly, but am not certain. Is there supposed to be a ground for the switch body itself? I have a custom dash that has a gloss black paint on it. I am not sure if the switch is supposed to ground itself to the dash or not, but that could also be the problem.

The switch needs to be grounded.

Ok, thanks I will give that a try

Well, I tried grounding the switch and that didn't solve the problem. The wipers just run Wide Open all the time unless the switched is pushed in to activate the pump, and it slows down. I applied 12v to each terminal seperately and the motor ran at the according speed, and when I grounded the motor body to the negative battery terminal, the wipers parked. But, I couldn't get it grounded anywhere else but the negative terminal. I have a feeling its something simple, but I am yet to figure it out. Please help!!!

The wires going to the switch are not 12 volt power wires. They are all ground wires.

Sorry for the confusion. I applied power to the terminals on the motor not the switch. I know there isn't any power running to the switch.

This help at all?
http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi/topic/22/2694.html?