Chevrolet Repair: 97 Chevy S-10, firewall one, wiper motor

Question
Wipers won't work but about 50% of the time. A guy at the inspection place said this is common on GM's and even passed it after he tapped on the wiper motor it started working. Is it easy to change the motor on it or will WD-40 work to assist it and make it more "consistent"...any advice would be helpful.

Answer
This IS quite common with GM wipers. Remove the 3 bolts that hold the motor to the firewall ONE AT A TIME and clean the bolts as you will see a copper strap that one of the bolts goes thru at the motor which is the ground circuit and if the bolt gets a little corrosion on the head of the bolt where the starp rests the wpers will not work.