I picked up a wiper delay from under the dash of a '74 ford pickup. Got the switch and box with the ground wire attached. I have read a couple of pages that said to get the motor, but some said to use the mustang wiper motor. I am thinking the motor doesn't matter, it's the box/switch that does the delay? I currently have a one speed in my 66 so what do I do to put this delay in? Thanks, gary.