wiper motor issue

[Greg H.]

I also have this posted elsewhere but hoping my new associates at the NCRS can help me out... My car is a 1970.

This started out as a simple job of clearing the washer hoses and I seem to be breaking more things as I go along. Probably just discovering problems of age in my 38 yr. old car, but it seems like the wheels are falling off.

I had the wiper motor out to repair the wires I damaged (the small red coil wires going to pins 1 & 2. Seemed ok at first when I tested it on the car. Motor went straight to park position, then on and off, high and low speeds. Then I saw some smoke.

There is a coil device mounted to the rear of the three pin connector (resistor, I believe). What is the purpose of this? It definitely gets hot and could be the source of the smoke (from my greasy hands maybe? - or something else - I see no melted insulation).

I removed the motor to investigate and it no longer runs, then I get physical and tap the relay with a screwdriver and it goes back to functioning properly, with smoke only at high speed. Low speed seems to be very happy. Makes sense since the resistor connects terminals 1 & 3.

I have the Service Manual and a paper by Willcox, which helped me get this far, but neither are enough to get me past this.

The questions I have are:
1) Should this "resistor" be getting hot? OK, if so, I just need to burn off the grease I inadvertently applied.If not, is there a replacemet device?
2) With the relay needing some physical encouragement, is there a replacement part available? Could be I limp along as it is but will be good to know.

Any help is appreciated.
Greg

[Alan S.]

Re: wiper motor issue

Hi Greg,
I also posted a reply to you on CF.
There's a good article about 75 wiper motor repair in the Summer, 1996 issue of THE RESTORER. It's by David Smith.
It could well apply to your 70 wiper motor, too. Let me know if you'd like a copy.
Regards,
Alan

[Edward J.]

Re: wiper motor issue

I Ll Try And Help, Im A New Comer. The Resistor Your Talking About Does Get Hot, Its Made To Absorb Voltage On Low Speed To Slow Motor Down, If You Got Grease On It It May Take Awhile For It To Burn Of. This Ballist Resistor Does Play A Important Role In Its Function Of The Motor.

[Greg H.]

Re: wiper motor issue

I Ll Try And Help, Im A New Comer. The Resistor Your Talking About Does Get Hot, Its Made To Absorb Voltage On Low Speed To Slow Motor Down, If You Got Grease On It It May Take Awhile For It To Burn Of. This Ballist Resistor Does Play A Important Role In Its Function Of The Motor.

Wow, Ed, you are a newer member than me - cool.

Thanks for confirming it should get hot. I think, however, it must be dissipating the power on the high speed setting as that is when I see smoke. It will run a long time on low with no sign of heat. But nevertheless if it is supposed to heat up I will let it clean itself off and see where that leads me. It looked like it had been hot before I dis-assembled the motor as it had a white chalky look to it.

If anyone thinks I'm going down the wrong path here, please chime in. I'm about to cook my wiper motor!

Greg

[Greg H.]

Re: wiper motor issue

Alan,
Thank you for the fax. This paper is very helpful. It gives the resistance of the resistor as 20 Ohms so I can measure that. It also states it connects to the motor housing which I can verify is a good connection. Thanks again!
Greg

[Alan S.]

Re: wiper motor issue

There is an incredible amount of useful information in THE RESTORER. I think we don't fully appreciate so many member's efforts over what is now becoming MANY years.
Regards,
Alan