I am replacing my old 1969 El Camino windshield wiper motor because of it being overall defective. I while installing the new one could not get the wipers to work. I was looking at the wiring checking it and then my grandfather who back in the day used to work in a garage on some of these older cars told me that some of the wiper motors ran off of vacuum to pull the wipers and assist the motor. I personally have never heard of this but I thought I would put this up on the forum and see if you guys agree and think I need a vacuum line or can give me some pointers on how to get these wipers working again so I can drive the car in the rain.

Thanks for the help guys,
69camino

Your 69 had electric wipers as did most Chevy's from about 58. The switch is a ground that can be directed to 2 points on the motor to change speeds. The motor should have a hot lead whenever the key is on. It also needs to be grounded to the body and this is done with a strap through one of the mounting bolts. If the motor and firewall have paint on them where the strap is attached it will not run.

This is a photo of a wiper motor with the washer assembly removed, the ground strap is in the lower left. The mounts are isolated from the body with rubber cushions so the bolt, strap and mounting area under the bolt at both ends need to be clean and bare metal to make a good ground.

http://i80.photobucket.com/albums/j199/64elcamino/parts/wiperparkswitch.jpg

One last thing, the dash is plastic so the wiper switch also needs to be grounded. Some are done with a metal strap and some with a wire at the mounting point.