Windshield wiper/washer issues

[jwgreen]

Hey guys,

Trying to figure out a little washer/wiper issue. So I have a 84 GMC with pulse wipers and washer. The wipers seem to work fine until I try to use the washer. When I press the squirt lever the pump just clicks and then the wipers stop working. Then the wiper will not start working again for some time, just random it seems. The wiper motor / washer motor I have has 3 plugs going into it. A 3 wire connector on the wiper motor, a wide 2 prong connector with a yellow and a light red wire and then another smaller 2 prong connector with what appears to be a grey or tan wire and a black wire. I can't seem to find a wiring diagram with this connector setup anywhere. I've checked and I'm getting 12v with the ign on to the yellow wire and about 2 amps on the light red wire at all times somehow. Anyone got any ideas or diagrams I can try or look at??

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[Snoots]

This may shed some light . . .

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[jwgreen]

Thanks Snoots I'll give the info a look over and see what I can figure out.

 

[jwgreen]

So I went and checked all the grounds and wiring according to Snoots post and all seem good. But this problem is still there intermittently so I'm guessing its going to be the module. Guess I'll order one and see if it totally fixes the problem. If not then I'm thinking maybe the washer pump may be bad???

 

[jwgreen]

So after more searching and testing it seems that maybe the ground in the column mounted switch is not as good as it should be. If I turn on the wipers and jump a wire from the ground wire on the motor to a known good ground point the wipers work more reliably and a little faster.

Question is, can I just leave that jumper ground hooked up semi-permanently until I have time to tear the column apart and replace the switch??

 

[PrairieDrifter]

I would almost bet it’s the pulse module. My wipers didn’t function when hitting the washer function or in any intermittent speeds, but worked on low and high. I’m 99% sure my pump is shot so I got an aftermarket pump and connected the leads for it to the original washer pump harness, so then I had washer fluid working on the multifunction switch but still no wipers working when hitting wash function, or intermittent.

I replaced the module and the system started working perfectly. I got mine off of summit for an 84 k10 for like 50 or 60 dollars.

I would do some more testing if you don’t want to spend that money, possibly for nothin. My problem was permanent pretty much, yours is intermittent, so you could just have a loose connection somewhere.

Get some other opinions as well.

 

[jwgreen]

I would almost bet it’s the pulse module. My wipers didn’t function when hitting the washer function or in any intermittent speeds, but worked on low and high. I’m 99% sure my pump is shot so I got an aftermarket pump and connected the leads for it to the original washer pump harness, so then I had washer fluid working on the multifunction switch but still no wipers working when hitting wash function, or intermittent.

I replaced the module and the system started working perfectly. I got mine off of summit for an 84 k10 for like 50 or 60 dollars.

I would do some more testing if you don’t want to spend that money, possibly for nothin. My problem was permanent pretty much, yours is intermittent, so you could just have a loose connection somewhere.

Get some other opinions as well.

I went ahead and got a module, but it didn't fix anything. Wipers are still intermittent but better and still a bit weak/slow but if I jump the ground they work a bit better.

 

[jwgreen]

Ok guys, so I replaced the module, replaced the switch in the steering column but still have a the slow/weak wiper situation. I still get a much better result when I jump the ground/purple at the motor to an additional ground. I've tested the all wires and I'm not getting any reading above .4ohms and I'm getting a full 12v at the motor. Any more suggestions?

 

[bucket]

The popping/ticking you hear is more than likely the washer pump mechanism malfunctioning. It's very common. It may also be binding and causing the weak wiper motor to stop working.

On my '84, I got a wiper motor for an '85-up that used a remote mount pump. Of the two 2-wire connectors, the larger one is for the washer pump. You can use those wires to power a universal electric pump, or to power an in-tank pump if you switch to the '85-up washer bottle.

 

[chengny]

Ok guys, so I replaced the module, replaced the switch in the steering column but still have a the slow/weak wiper situation. I still get a much better result when I jump the ground/purple at the motor to an additional ground. I've tested the all wires and I'm not getting any reading above .4ohms and I'm getting a full 12v at the motor. Any more suggestions?

You probably know all this, but anyway:

There is no single ground lead for the wiper motor - the high and low speed windings are connected to their associated brushes. Each of those brushes is ultimately connected to ground via the control switch. The position of the control switch determines which of these brushes is grounded (or neither). When you ground the PPL lead you are running the motor on the high speed windings. So it will probably appear that performance improves - or at least compared to low speed operation.

In addition to the HI/LO speed brushes there is another brush that feeds the other side of both sets of windings. They call that the common brush. The common brush is always supplied with battery voltage - whenever the key is in RUN/ACC. Moving the control switch to LO connects the low speed brush to ground. When set to HI, the low speed ground path is opened and the high speed brush is grounded.

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So if both speeds seem to be running slower than expected, it would probably either a worn common brush or a poor ground path - from the switch to the common ground bus block. If only one or the other speeds was slow, that might point towards a single worn brush.

You're getting good readings on both the HI/LO speed (PPL/GRY) ground legs as well as full battery voltage to the common brush. But - and this is where I get confused - you see a marked improvement:

when I jump the ground/purple at the motor to an additional ground.

That's running on high speed.

What if you ground the gray lead and run the motor on the low speed windings? Does that get better results than grounding through the switch as normal operation?

If you have 12 V on the WHT, good continuity on both ground legs and a new switch/module...and your motor speeds up noticeably when the brushes are grounded to a nearby spot on the body, IDK. Maybe try cutting into the ground wire that runs from the control switch to the common bus block and running a jumper straight to the bus block:

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