Rear Wiper Problem

[Backdraft]

I have a weird problem with the rear wiper. When i flip the switch, the wiper doesnt move but the relay starts to buzz real fast. The wiper motor is fine, but im stoopid when it comes to relays and more complex wiring. I havent got a clue where to start on this, so anyone with an idea as to what could be causing this please let me know. Thanks


Mike

 

[8Mud]

Think the relay is in the tailgate? I´d guess a corroded connector or bad ground could be the culprit.
But what I´ve found, on more than a few occasions, is that the grease inside the wiper motor, has turned to the consistancy of modeling clay, after 14 years. Turn the switch on, and help the wiper along a little by hand, don´t force it much, a steady pressue on the wiper arm. If you can feel it trying to work, it´s likely that the motor needs to be cleaned out (a spray can of brake cleaner works well) and add some new grease. Don´t try removing the gears, I´ve done it a pain. There is a park contact/switch under the large gear, that is easy to damage (ask me how I know this). If your park contacts burn up, a little rewiring, will let you park it with the wiper switch.

 

[Matthew Currie]

Think the relay is in the tailgate? I´d guess a corroded connector or bad ground could be the culprit.
But what I´ve found, on more than a few occasions, is that the grease inside the wiper motor, has turned to the consistancy of modeling clay, after 14 years. Turn the switch on, and help the wiper along a little by hand, don´t force it much, a steady pressue on the wiper arm. If you can feel it trying to work, it´s likely that the motor needs to be cleaned out (a spray can of brake cleaner works well) and add some new grease. Don´t try removing the gears, I´ve done it a pain. There is a park contact/switch under the large gear, that is easy to damage (ask me how I know this). If your park contacts burn up, a little rewiring, will let you park it with the wiper switch.

On rust belt Jeeps, the other thing that can go wrong is that rust gets into the shaft and bushing, and it stiffens up and eventually seizes. It's very common. To fix this you may have to get remove the gears to press the shaft out and get some grease in there. If you wait too long it will strip the gears inside or burn out the motor. Very expensive.

 

[Churchlady]

Glad to sit in on this. My rear washer shoots a full stream of fluid about 8 ft. straight back instead of forward. Is this a malfunction or an ingenious way to discourage tailgaters?

 

[Eagle]

Glad to sit in on this. My rear washer shoots a full stream of fluid about 8 ft. straight back instead of forward. Is this a malfunction or an ingenious way to discourage tailgaters?

Heh, heh --

Mine did that when it was new.

There is supposed to be a hose that runs along the wiper arm to spray water/cleaner directly onto the glass as the blade sweeps across. The hose presses onto a stub that extends out of the base of the wiper shaft housing.

Your hose has fallen off.

 

[Matthew Currie]

Glad to sit in on this. My rear washer shoots a full stream of fluid about 8 ft. straight back instead of forward. Is this a malfunction or an ingenious way to discourage tailgaters?

I think this counts as a malfunction, though it could have its uses. There's supposed to be a little hose that attaches to a very small nipple on the plastic bezel around the wiper shaft, and then leads up through the arm. If you're lucky, the hose has just come off or broken somewhere. If you're not so lucky, the little plastic nipple has broken off, and you'll need a new bezel.

 

[OT]

Of course, since you're not in the rustbelt, it's probably just a piece of crap.

If it turns out to actually be a piece of crap, let me know and you can have mine, as it worked when I pulled it out. Just pay shipping.

 

[Backdraft]

The relay is in the tailgate on mine, dunno about others. As far as the motor goes, I disconnected the plug and hotwired it to the batery to make sure it wasnt the problem, and it did work. Turning the thing on and trying to push it along by hand is a no-go also. Ive tried a couple different relays with the same buzzing effect. Its looking like a short/ground/undervolt problem to me.

If i cant figure this out soon Ill end up rewiring the whole thing. Terry, if this thing disagrees with me too much I might just be interested in your motor and stuff. This thing sees trails, but my wife also steals it from time to time, and wants the wiper to work.(women drivers )


Mike

 

[GomerP]

I also had the pleasure of having my rear wiper shoot water 8 ft behind me. I also had the luxory of being chased for a good half hour when we sprayed the wrong cars windshield. Most people think it is pretty funny, but some of them you just have to pass on. To fix it all I did was reattach the plastic tubing to the nipple.

 

[Don Becker]

Okay, I'll share my story too . . . . recently, on our 91 XJ, I had the stream shooting straight up in the air that same eight feet and the hose WAS attached . . . . 'looked at the end of the wiper arm, 'couldn't really figure-out what had gone wrong so I replaced it with another arm from my U-Pull-It collection - - - el-fixo! (Every trip to U-Pull-It, I come home with more XJ "stuff"/spares/I'll-need-this-someday than what I went in looking for. I want to thank all of you fine fellers who remove parts/pieces/bolts/screws/nuts and then just leave them laying loose in the donor vehicle for me to latch onto!) Don


Gee, now that I'm thinking about this, I put that "eight-feet-up-in-the-air-arm" back into my parts box . . . . 'guess I'm gonna be in for a surprise one of these days...............................

 

[Cherokee91Red]

I've got another problem with my rear wiper motor. I have tried 2 different motors and both have same result. The relay clicks like its trying to move. I have taken both apart and sprayed them and cleaned em. They move freely with force on the gears. I dont have a clue as to what the other problem might be. Electrical is far from my strong point.

 

[Go Go]

I've considered removing the hose just to shoot water at people. Glad to know it works.

 

[Backdraft]

Id like to thank the last few non members for keeping my thread on topic to help me solve this problem


Mike

 

[Churchlady]

Mike, I apologise for being the Judas goat who got everyone off topic. I'd just discovered the backward spray phenomenon when I saw your "Rear Wipers" thread & it seemed like a godsend. But I realized almost immed. after posting it that you have a quite different & far more serious problem. I'm really sorry.

(But there's something fraught w/possibility about that beautiful arc of water jetting out the back of your car. World's fastest water-gun.)

 

[Backdraft]

No prob Churchlady, its just frustrating when a simple problem becomes more clever than you are, ya know.


Mike

 

[8Mud]

The green wire is the switched current to the relay, the yellow wire is constant voltage, to park the motor (kind of a guess, haven´t messed with the motor in awhile, could be vice/versa). I´d try unplugging the yellow wire and see what happens. There is also a diode (they put in there for a reason?) on the motor, that if bad, could probably make the relay vibrate (sing). The diode could be bad, by allowing the current to run backwords and/or have developed a resistance.
Could be a short in the system (probably the park switch, behind the drive gear) that is running so much current to ground, there isn´t enough left to activate the relay, consistantly.
I´d unplug the motor (hot and ground) test the power leads to, the motor case (ground), with an ohm meter. A test meter with more than six volts of supply voltage, works better, when chasing shorts through moisture.
On mine, I took the diode out of the system, hooked the green wire directly to the motor lead, disconnected the yellow wire (took the park out of the system, making the diode unnecessary) and now park the motor with the switch.
Your motor gear housing (park switch) could be mostly full of water, gets in there through the shaft, the bushings become worn and loose. The park switch ends up as a rusted glob, that shorts to the case.
Amazing how such a simple thing can cause so much aggrivation, been there done that.

 

[Matthew Currie]

If you get really frustrated and you're sure the motor is all right, you could always just bypass the relay and let it run continuously like the old ones.

 

[Backdraft]

Thanks for the extra info guys. Ill use it to try and get it to work. Now if I can find some time to do it, itd be even better.


Mike