ajrothm

I have something weird going on, and for the life of me, I can't figure it out.

My wipers were working fine back in June, well right before the Power Tour, they stopped working. I tried to troubleshoot them then and found that I had 12v power to both points on the motor, I could hear a click in the motor when changing the switch positions, telling me the relay is working etc.... So I figured the motor itself went bad.

Today I pulled the motor, hooked it up to my truck battery with jumper wires and the motor would not run, so I figured it really was dead. I go get a new wiper motor, install it and guess what, no workie.

I have 12v power on the middle wire (yellow) on the 3 slot plug, I have 12v power going into the motor itself (big red wire)...I have verified 12v at both of these points. That tells me its not getting a ground signal. So I jumper a ground signal to one or both of the outside slots on the 3 slot plug and I get nothing but clicking.

I removed the wiper arm shafts from the motor to make sure that the arms are not binding up the motor..

So can someone tell me what I am doing wrong to make this motor run manually? I've watched Wilcox's videos and it seems I'm doing it just like them in theory.

I am absolutely stumped by this....


FYI
Since I am getting 12v to the big red wire at the motor, that eliminates the bypass ****/wiring, and the wiper door switch and wiring, so I know its none of that stuff.



Thanks in advance for any help.

'75

The motor needs a ground to the housing, then has a power wire, then the switch grounds different windings in the motor to get different speeds. Make sure the switch at the gauge panel has a ground.

0Willcox Corvette

I would still bench test the new motor.. this takes the motor out of the equation.

If you are hearing the relay click.. and you really have to listen to the console.. but if the relay is clicking the wiper switch is grounded..

If there is a breakage in the yellow wire the relay will engage and click... but the motor will do nothing.

Go watch the following videos... and upload the schematic. Your answer is in the video or the tech page for wiper diagnostics for 1969-1972.

Willcox

Here are the main articles and videos on the web site to help you.

Upload this first... http://repairs.willcoxcorvette.com/w...-with-test.pdf

Then review the items at this link. http://repairs.willcoxcorvette.com/p...t=1969&s=wiper

And then review the following.... you'll find your answer.

Video on testing the motor:
1969-1972


Video on testing the switch


Wiper Motor Bench Test 69-72


1969-1976 Corvette Wiper Motor Bench Testing and Some Relay Repair Help


Ohhhhhh sooooo Free Simple schematic.



Willcox-
18243

ajrothm

Ok I figured out the first problem. Apparently the washer pump assembly was putting the wiper motor in a bind. Running the wiper motor without the washer assembly on it, everything works fine using the car’s wiring and switch.

I went through the washer pump assembly, cleaned/lubed everything and made sure it was in the Parked position before reinstalling it.

So then after reassembling everything, the sucker was bound off again, this time it is something with the wiper linkage causing the motor to bind.

So tomorrow, I’ll be back at it trying to investigate that.

Here is my test without the washer pump

Richard454

**************NEVERMIND!!!************** *


Like '75 said-

The case has to be grounded - the hi/low speed plus park is controlled by a combo of grounds-AND a shunt (resistor) is used for low speed...

Here's a pic- if this helps

ajrothm

That’s a great pic! Thanks for posting.

Now I know everything in the wiring/switches and grounds are good, I just have to figure out what is mechanically binding the motor in the linkage.


It’s always something...lol😅

ajrothm

Thanks for the help as always! You guys are the best! I’ve got a BIG order I’m about to throw your way in the next month or two when my car goes to paint.

ajrothm

Well I got them going...still messing with adjustments and trying to get them to park correctly so the door will shut.


After this video, I pulled the wiper door off (talk about opening pandoras box!) I was cleaning/lubing the linkages and decided to clean the 46 years worth of mud in the wiper trough....chiseling, scraping, vacuuming and washing for hours, I got it half *** clean. Got the wipers parking and hitting the limit switch. Now I just need to get the wiper door back on which is an epic pain in the ***... I gave up for the day. Maybe try again tomorrow.


Oh and my washer system still isn’t working.

ajrothm

New wiper motor and cleaned up/inspected the old washer pump.




Cleaning out this 46 year old mess.... It was 1/2" thick or more in some places.... I literally chiseled out..






Got down to bare fiberglass is most of the trough..


I cleaned and lubed the arms/joints etc... now I need to paint the trough, and get the wiper door back on which is proving to be a major pain in the *** with the spring loaded mechanisms..