Every now and then my wipers will not stop. They'll run for 10 minutes or more.
Is there an adjustment for this?
Is there an adjustment for this?
Wipers intermittently fail to "home".
- Thread starter Brian in Oregon
- Start date
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The dash wiper switch has a wire that is hot when in the off position. It's either the LW or LB wire, I forget which, but it is easy to figure out with a tester. What that does is run the motor until a detent ball in the large gear off the motor itself comes around and bends the contact blades in the on board wiper motor switch away from each other, which then cuts the current from that wire to the motor. That switch is behind a black plastic cover on the front of the p.s. wiper. So, your problem with run-on probably is occurring because the ball is too worn to push the blades apart. You may be able to get into the on-board switch and adjust/bend the blades to get it to work again.
- Thread starter
- #3
Thanks, will give it a whirl.
Not to hijack, (even though I am, sorry). Dave, are you saying that the wipers will stop automatically at the right spot? Mine stop just fine, but only when I turn off the switch. In other words, whenever I turn off the switch, the wipers stop no matter where they are. I assumed this was correct. From your post, it seems they should stop at the "correct" position on the windshield(i.e. off to one side), and not when I turn off the switch. Currently, I have to "time it" when I turn off the switch to get the wipers to stay at the top of the arc. This is on a 71 fj40. Is this correct? I'm just curious.
Thanks!
Thanks!
I'm not Dave, but I can tell you FF that is correct. The wipers should "park" out of the way when turned off. The ball switch Dave described is in my wiper's and I have a '72.
FF LC FREAK
I have a '71'. Your wipers should park themselves in the upper position at the top of the windshield no matter where they are in their cycle and no matter when you turn off the switch. Mine does, they function properly except for being slow.
I have a '71'. Your wipers should park themselves in the upper position at the top of the windshield no matter where they are in their cycle and no matter when you turn off the switch. Mine does, they function properly except for being slow.
On my '74, the wipers swing from the top of the windshield. I had a problem where they wouldn't "home", intermittenly. I could hear the wiper motor slow down in the home position, but the motor would coast past the "home" position and wind back up to wipe again. It would do that for a while till something, probably frictional forces, allowed it to stop in the home position. I ended up adding a small amount of preload to the drive bearings on the wiper motor,(the little nut with what looks like a screw inside). I have not had a problem since. I started having this problem after I overhauled the entire wiper assembly. It ran a lot faster after that. BTW> the wiper motor bearings are a single steel ball that sits in a "cupped" tip on each motor shaft end. The preload can easily be out of adjustment, and can be tricky to get set right.
Colorado Boy-74-FJ40
I may grow older but I refuse to grow up!
Brian, I've been here before. Come by sometime.
Cool, thanks. I never really thought about it, since it has done this as long as I can remember (even as a little kid - yes, the rig has been in my family a long time - see my ROTW if your curious). I guess I'll tear into my wiper motor and see what is up.
Thanks again!
anybody had a pic of the black cover for the off-position siwtch for a '72?
IDave's has a hole for a screw, so I suppose that was an earlier design. There is no provision for screwing down the cover in my truck, so I was wondering what the OEM situation looks like on a '72
IDave's has a hole for a screw, so I suppose that was an earlier design. There is no provision for screwing down the cover in my truck, so I was wondering what the OEM situation looks like on a '72
My wipers don't return "home" either. My windshield washer decided to take a dump at about the same time. IDave, could you describe the fix in a little more "basic" terms? lol I have a '77, I guess I don't understand if the fix is in the switch or the motor. Thanks!
Dianna, I don't know how a later truck wiper mechanism works.
All I have pulled apart is the 68-74 version I share with Brian and Claudia. The FSM doesn't have helpful diagrams, or a description, so I'll do the best I can to describe the mechanism with pictures I took of my parts wipers.
Here is the ball pin that runs the switch in the wiper motor (reddish thing).
It fits into the front, as shown, the stem coming out of a hole in the back of the housing underneath the big gear.
All I have pulled apart is the 68-74 version I share with Brian and Claudia. The FSM doesn't have helpful diagrams, or a description, so I'll do the best I can to describe the mechanism with pictures I took of my parts wipers.
Here is the ball pin that runs the switch in the wiper motor (reddish thing).
It fits into the front, as shown, the stem coming out of a hole in the back of the housing underneath the big gear.
The big gear has a raised area underneath it. As it comes around, the raised area pushes the pin/ball switch up, which opens one blade-blade contact, and closes another.
Here is the black cover, in place. One screw in, one out.
So, you can see it's the LB (Lavender with black stripe) wire that is the hot one for the "park" function of the wiper motor.
While the middle blade contacts the lower blade, the motor has power and continues to function. As the raised area on the big gear comes around and pushes the pin, the middle and lower blades lose contact and the motor stops. That's your park position. Adjust your wiper blade arms accordingly.
So, you can see it's the LB (Lavender with black stripe) wire that is the hot one for the "park" function of the wiper motor.
While the middle blade contacts the lower blade, the motor has power and continues to function. As the raised area on the big gear comes around and pushes the pin, the middle and lower blades lose contact and the motor stops. That's your park position. Adjust your wiper blade arms accordingly.
- Thread starter
- #17
Nice pics and write up!
I have both, Claudia, The one you have is supposed to just snap in place but I do not think the covers are available any longer. I got a motor from Fast Eddy with the screws and cover intact.
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Fascinating.
And I thought I was the only one with this embarrasing problem.
Rocky
And I thought I was the only one with this embarrasing problem.
Rocky
