1994 Chevy Blazer 1994 S-10 Blazer wiper problems

I have a 1994 chevy S10 blazer with wiper problems. When I turn the wipers to a intermittent setting they turn on and stop working at the top end of one cycle. They also cycle 3-4 times before shutting off (in the wrong position) when turn them off of the low and high settings. Also the washers will not work now either. I have replaced the switch in the steering column, the wiper motor and the wiper pulse board on the wiper motor. The wipers did work for a short time when the motor was replaced and then stopped again. The same thing happened when the pulse board was replaced. Is there something that I am missing? Can anyone help me with my problem?