Alb

This is driving me crazy and in my case that is a short trip. Put in a new wiper motor on my 69 Cutlass. When I turn them to the first position, they goes fast. When I turn it to fast it still goes fast. I tried another motor and the same thing happens. Tried a new switch, same thing. Any ideas ?
Alb

Octania

poor grounding of the switch at the dash?

The CSM has a great troubleshooting procedure to pinpoint the error.

wildaboutcars.com

joe_padavano

The two speed wipers have an unusual wiring scheme. There is a primary winding in the motor that gives you high speed, and a reverse-wound shunt winding that is used in conjunction with the primary winding to give you low speed. If two new motors have the same problem, chances are the wiring to the shunt winding has an open circuit, somewhere from the switch to the wiper.