69 Chevelle Wiper Motor will not turn off
 

Hi Gents,

I'm working on a 69 Chevelle for a friend. Basically finishing the last 5% of a restoration. Before I buttoned up the dash today, I tested the wiper switch and motor. It turned on, both speeds worked and when I shut it off, the motor parked and turned off. I didn't have the wiper arms on at this point. I subsequently put on the wiper arms and blades. Gave it another go and the motor will not shut off or park at this point.

Anyone been down this road before? Before I start taking the dash or anything else apart, I'd like to see if anyone has a good starting point to diagnose this.

Thanks.

Phil Woj.

I am not specifically familiar with the 69 Chevelle wiper motor, but I believe they all work similar in that the center terminal is 12 v hot all the time. The low speed terminal is grounded to start the low speed cycle. The high speed terminal is then grounded along with the low speed to achieve high speed wiper action. Then the high and low grounds must be removed in reverse order for the motor to park. My guess is the low speed wire is inadvertently grounded not allowing the motor to stop. remove the three prong plug and test either two outside terminals to see if you get zero-low ohms with the wiper switch in the off position. If you do...start tracing it back to the switch from there....could be wiring or could be internal to the wiper switch. Hope this helps

mine did that as well, check the wires on the switch and I also wound up buying a new motor.

Thanks for the replies. I will get the VOM out tomorrow and start testing.

Phil W.

It ends up the problem is in the motor assy. I hooked up an NOS one to the wiring and each switch position functioned normally.

Thanks for the input.

Phil W.

Good deal Woj. I am going thru testing phase right now with mine. Waiting for a magnetic switch to come in which controls the parking function of the wipers.

Good to hear it was just the motor assembly...chasing wires can be very frustrating.

I had the very same issue. The motor will not stop until it goes into park position. A coil holds the parking paw until until the switch is turned off. At that time the paw drops out and causes the blades to go to park which breaks contacts to stop the motor. The coil that holds the parking paw is not releasing, be it mechanical or electrical. With mine it seemed there was residual magnetism holding the paw and keeping it from activating. I could not find a mechanical cause. I replaced the coil assembly with a used one and problem solved.

Is this something that can be repaired easily, or should it be sent out to someone who has already done this? The motor looks to have been restored already, but I'm not sure who did it?

Woj - my 49 y.o. motor looks pristine/new and was never restored. They are really encapsulated in there well. So your bud's motor may or may not have been restored. there is an adjustment screw (with a nut to secure it in set positon) at the end of the motor drive shaft that can be adjusted and will affect where the brushes contact the motor. You might check that that is set right.

The motor I had issues with was a fresh rebuild from a major Chevelle parts supplier. The coil was brand new. The coil can be replaced by heating and resoldering 3 or 4 connections. No need to disassemble the whole motor. Do remove from the car. The coil is located behind the washer assembly and under a plastic mounting fixture retained with one screw. The fixture and 3 power tabs should lift out as a unit. TAKE CARE NOT TO BREAK THE RESISTOR that is located below. You will need an old wiper motor for parts. New parts may be available, but I have not researched that. New parts may be the same as was used in my newly purchased rebuilt unit.

Every time I had a weird problem with a wiper motor it turned out it wasn't grounding well.

I had mine on the car and connected directly from the battery to the wiper body with jumper wires and alligator clips. The linked video shows the correct way to bench test your wiper motor. A little crude but very good information.

https://video.search.yahoo.com/searc...c4&action=view

That is a really good video. I will follow his advice.

Thanks for the link.

Phil

A big thank you to those that responded to my question. It was the magnetic switch that initiates the parking action that failed on my wiper assembly. The link to the wiper-motor-test video isolated the problem. I then spoke to the new wiper assembly expert, Sam (Mockingbird), who told me what to order and where. Installation took about 10 minutes and everything works as it should.

Thanks again, I couldn’t have done this without the help offered here.

Phil W.