I looked on Mid Fifty, Classic Haulers and Dennis Carpenter. I see lots of instructions on Mid Fifty, but they're for Mid Fifties, not ours. No such instructions on Classic Haulers or DC.

The stock wiper motor has 3 leads. The case is grounded to the frame. The switch has 4 leads, all hot at some point. One is the voltage supply.

The way the original parks is by applying the same voltage to two contacts at the same time, equaling them out, and providing 0 volts difference in potential. It took me a while to figure out how that worked.

So, with 5 wires, I have to assume you have a ground, high speed, low speed and park. I have no idea what the other wire would be. Sorry.

Call Classic Haulers.