Windshield wiper motor

[Andy Higbee]

Have a question for someone with experience on working with WW motors. My 71 had a wiper motor that had sat in rain, partly flooded, for a long period and did not function. Before sending it out to an expert for repair thought I'd give it a try by myself, will I never learn. That from my wife!!

Anyway after tearing down, cleaning and reassembling everything appears to work but I have a few questions not answered in the GM shop manuals or any others that I can find. Before I install this and have to take it out later your answers would be greatly appreciated.

First, does the nylon drive gear operate in the same direction for both low and high speed, mine has a different rotation from one to the other, CW for high, CCW for low. The shop manual indicates CW looking down at the gear but doesn't indicate which mode of operation. It runs great, of course theres no load.

Second, when the wiper coil is energized and causes the wiper drive gear to rotate with the drive gear(wipers operating)should the coil that operates the
washer mechanism be energized or not. I'm having a difficult time understanding the sequence of the seperate coil operations in each of the modes,
wipers off and home
wipers on slow
wipers on fast
wipers on with washer

Sorry for the book just trying to get some answers. Any help would be appreciated.

[Tim anderson]

Re: Windshield wiper motor

I'm no expert at 71 vette but I have discombobulated (spelling?) and repaired other GM wiper motors. And since no one else took a shot at it. Here's mine.

I can't imagine the washer (coil? maybe motor windings) being energized unless the washer function is active. But you could be talking about the park relay. Yes it is energized at any time the wipers are moving and the command came from the switch. (i.e. slow, fast, intermitant or wash) it keeps the wipers from parking.

As for the reverse I think the only time reverse should happen is after power is removed and end of cycle. Reverse happens to send the wipers to the park position. I've never seen any of my wipers backup in mid stroke switching to high.

Don't forget to use the factory harness and switch when testing. High and low speed typically are achieved by grounding with and without a resistor.

That resistor SHOULD be inside the wiper motor, but yours is older than any I have fooled with so...........Just applying power from a battery might not give the same results. Any how high and low would be achived by changing the ground wire not the power wire.

Hope this helps.