Wiper Motor Issues

[Steve McMahan]

I’m having difficulty with my wiper motor. Doing general checks after I completed the wire harness for the new FI motor, I noted I had power to the Red and White wires with the key on. That jived with the wiring diagram, wiper on low speed. So when I connected the existing motor to the updated harness, I got nothing, no wiper movement. I Re verified I had 12v at both of those wires, but no movement. So I unfastened the wiper arm mechanism at the motor’s crank. Still nothing, so I ordered a refurb Cardone 40-265 from Amazon and thought all was well.

I replaced the connector on the motor with one from WCCC. The motor had 4 wires, same color as the original, although slightly different. Put it all together and got nothing. No motor sounds, zip. Reverified I have the power to those two wires, but nothing.

I‘ve tried to verify continuity inside the motor but want to verify with the community where I should get that. Based on the 73 Wiring Diagram, segment shown below, I should get continuity between the White and ground? I’ve got no continuity between the Red and ground AND I’ve got none between the BK-P and ground. At least that should be showing continuity. It’s like I’ve got no ground. Now, I did verify the ground strap at the back of the motor was there.

It was work to install and before I pull it all off again, what else can I do?

 

[Steve McMahan]

I’ve got an update. I removed the unit and determined I did not have a ground between the case and the frame. But what I don‘t understand is that I don’t have continuity between the BK-P wire and the case. This is one of those refurbished that add that short set of wires from the short wires to the motor. I’ve gone on the motor side of that black heat shrink tubes wires to see if the one on the BK-P wire was showing continuity and it made no difference. At least from that it seems the case and the BK-P wire are not connected.

If I use my Powerprobe, power to either the White or Blueish wire and use the case as the ground, I can get it to work. So, I discovered the case to frame ground issue was that weird brass-ish ground strap. I thought I cleaned it before installing it, but I discovered when I removed that one isolator grommet, that the inside of that strap was very corroded. A quick cleaning and reassembly showed the case was reaching the frame ground.

I reinstalled the unit and it works and parks.

Now, for problem number two. The passenger side wiper is not close to the parking position when the drivers side is. It seems that knurl (if that’s what it’s called) at the backside of the bracket is loose. But looking at the amount of allowed deflection to the center, it’s still 45 degrees more advanced than it would be in the parked position.

I‘m wondering if I should grind out that last knurl and locate it where it should be at park and put a few tack welds to hold it? The first two pictures show the relative position of the passenger arm holder to the wiper levers in both extremes of looseness to the bracket, and the final pic shows that knurl place that holds the passenger arm holder in place.

For reference, none of those long wiper levels (what I’m calling those long arms the motor drives to the wipers) are bent. My question is what I’ve said above, can I just move that passenger arm where it goes and tack weld it OR is that a fool’s errand and I need a new/used one?




This is the parked position for the passenger side, way off:

 

[Sheriff41]

Steve, I'm impressed with all you've done with your car to this point. Your determination and progress are fun to follow. Keep up the great work!

 

[rackerm]

I’m having difficulty with my wiper motor. Doing general checks after I completed the wire harness for the new FI motor, I noted I had power to the Red and White wires with the key on. That jived with the wiring diagram, wiper on low speed. So when I connected the existing motor to the updated harness, I got nothing, no wiper movement. I Re verified I had 12v at both of those wires, but no movement. So I unfastened the wiper arm mechanism at the motor’s crank. Still nothing, so I ordered a refurb Cardone 40-265 from Amazon and thought all was well.

I replaced the connector on the motor with one from WCCC. The motor had 4 wires, same color as the original, although slightly different. Put it all together and got nothing. No motor sounds, zip. Reverified I have the power to those two wires, but nothing.

I‘ve tried to verify continuity inside the motor but want to verify with the community where I should get that. Based on the 73 Wiring Diagram, segment shown below, I should get continuity between the White and ground? I’ve got no continuity between the Red and ground AND I’ve got none between the BK-P and ground. At least that should be showing continuity. It’s like I’ve got no ground. Now, I did verify the ground strap at the back of the motor was there.

It was work to install and before I pull it all off again, what else can I do?

View attachment 74652

Is the brass ground strap clean and making contact with the wiper base and the one mounting bolt? You can see the strap in the pic below on the lower right bolt hole.

 

[Steve McMahan]

Thanks Sheriff41. I’m Irish, so I’m a bit stubborn. And, I enjoy trying to fix something verses replacing it. Now, I wish I was as talented as many on this site at that. And I’m getting close to that place where I could drive it when I want to. So, while I don’t suspect I’ll need wipers in AZ, I need to fix this. This looks like a hard part to find.

 

[Steve McMahan]

Is the brass ground strap clean and making contact with the wiper base and the one mounting bolt? You can see the strap in the pic below on the lower right bolt hole.
View attachment 74668

Yes, I did discover that was not working, and I got that fixed. What I cannot jive is the black wire going into the unit not being a ground. There is no continuity between that wire and the frame ground. I’ve got the motor working ok now, both low, high, and park, by fixing that crusty ground strap. Now, I need to figure out how to ”repair” that passenger side “pivot shaft and link assembly” (I finally looked up the official name).

 

[Steve McMahan]

Well, I fixed it. The process wasn’t difficult. The biggest issue was keeping the felt like washer at the bottom of the pivot from burning up in the welding process. Here’s what I did:



I started with this pivot pin miss located in relationship to the passenger arm at park. It was about 40 degrees too far extended from its park spot, kind of mid window. So, I carefully ground off that pinning or knurl, call it what you may. I ended up with these parts:



The pivot where it attaches has a felt like washer between the bracket and the pin. I knew I was gonna end up welding that pin to the bracket, so some way to preserve that was something I wanted to do. I measured the pivot shaft and found it to be .325”. I drilled the hole in the bracket to 21/64”, about 1/2 a 64th larger than the pin. That gave me a very snug fit so I would only need small welds later. So, I reassembled, added some felt protection measures, placed it where the geometry said it should go and put a tack on it:



Not very pretty, but it held. I reassembled the mechanism to the car, and ended up with this:



Close, but not enough clock movement. The black mark on the windshield was were it started. It’s hard to see, but there are marks on the WS to mark the final location, but I missed it by 8-10 degrees. I pulled it off, removed the two tacks, added the 8 degrees, did a more final weld because I was certain it would work. I put weld through primer on the weld, just in case, reinstalled it, and attached it to the motor, and bing, bang, bong, it worked. Maybe 6 degrees would have been better. The parking is tight on the passenger side, perfect on the drivers side.



And they work great. Thank you for the help. Steve