Windshield Washer Motor

[mightyatom]

My trucks windshield washer has never worked. I assumed it was the washer pump motor so picked up a replacement from the scrapyard but still nothing. Is there any way I can pull the washer pump motor from the windshield wiper motor and hook it up to power/ground and bucket of water to check it is working ?

Also as they have never worked I am assuming that the washer is activated by pushing in and holding the wiper motor switch on the instrument cluster. Is this correct ?

Thanks

[hvychve]

The washer pumps are mounted on the wiper motor and were tempermental, if you are not very conscientious of originality, go with a remote mount on your bottle , run power from the ckt that supplies power to the original, or bend down under dash and install a new one, relatively cheap, I dont know if I were to chance it on a junkyard pump, unless I sent power to it and found it to work, still I dont know about used.

[dsy1]

The gaskets and o-rings get brittle and won't hold pressure. A used one from a junk yard may still have the bad o-rings. You can get a repair kit for about $10, but if the main piston seal is bad the repair kit won't fix it. A replacement from the local parts chain store was only $27 when I did mine last week. Plan to replace all your rubber hoses at the same time. The only hard part is getting to it, you should probably remove the radio and the top AC vent to get better access.

[eightbanger]

Originally Posted by dsy1

The gaskets and o-rings get brittle and won't hold pressure. A used one from a junk yard may still have the bad o-rings. You can get a repair kit for about $10, but if the main piston seal is bad the repair kit won't fix it. A replacement from the local parts chain store was only $27 when I did mine last week. Plan to replace all your rubber hoses at the same time. The only hard part is getting to it, you should probably remove the radio and the top AC vent to get better access.

x2.

[truckster]

Originally Posted by hvychve

The washer pumps are mounted on the wiper motor and were tempermental, if you are not very conscientious of originality, go with a remote mount on your bottle , run power from the ckt that supplies power to the original, or bend down under dash and install a new one, relatively cheap, I dont know if I were to chance it on a junkyard pump, unless I sent power to it and found it to work, still I dont know about used.

I'm with hvychve; unless you're keeping it 100% original, I'd go with an external pump. They work much better and they're more dependable. Wiring is simple, too. And you don't need to remove the wiper motor for the install.

[mightyatom]

Many thanks. I am not worried about keeping it original but I have removed everything from under the dash to clean up the wiring so have good access at the moment. I thought it would be easier just to replace the washer pump as I did with the one I got from the scrapyard, rather that drilling holes and running wire to a new pump in the engine compartment.
I don't mind spending the money on a new pump but want to make sure the pump is the issue and not the wiring. Is there any way to run the pump out of the car or check the voltages on the connector of the pump ,just to make sure it is not the wiring that is the issue ?
Also can someone confirm the washer is activated when the wiper switch is depressed, just to verify my expectations are correct ?

Thanks

[LockDoc]

-
Yes, pushing in on the knob starts the washer pump and turns the wipers on low speed.

LockDoc

[dsy1]

The piston on the pump runs off a lobe/cam on the wiper motor. The electrical connection on the pump activates a solenoid to engage the pump when you push the wiper switch in. If you remove the pump you can see if the solenoid is working, but the pump piston won't move unless it is still mounted on the wiper motor.

If you have good access you can run a rubber hose to the inlet side from a jar of water, and see if the pump sucks up the water and pushes it out the outlet hoses. If you leave it attached you should be able to hear the pump cycling (a repeated clicking noise) if it activates. If not, check your switch or the wiring from the switch to the pump.

[mightyatom]

Still no luck so far with this. I tried installing a pump repair kit into the original and scrapyard part and still no luck with either. I checked the yellow and dark blue wires at the washer pump connector and have the following:

ignition off -> darkblue(0V), yellow(0V)
ignition on/wiper switch out -> darkblue(0V), yellow(12V)
ignition on wiper switch in -> darkblue(0V), yellow(12V)

It looks like the yellow is the ignition switched power so am wondering what the dark blue wire should have on it ? Also, can someone confirm the the darkblue wire should be on the top pin, yellow wire bottom pin, of the connector with the pump oriented with the hoses at the top ?

With the pump removed I can see the wiper motor turning the yoke and when I connect darkblue(GND) and connected/disconnect yellow(12V), I hear the solenoid clicking. But when in place the pump is still not pumping.

Any help appreciated.
Thanks

[leddzepp]

Originally Posted by truckster

I'm with hvychve; unless you're keeping it 100% original, I'd go with an external pump. They work much better and they're more dependable. Wiring is simple, too. And you don't need to remove the wiper motor for the install.

x 2

[mightyatom]

As the washer pump has never worked I want to make sure that the connections are correct. Can someone confirm that the connector is attached to the washer pump correctly in the photo (darkblue top/yellow bottom) ?


I would also like to verify the voltages I am seeing at the connector itself to make sure it is not a problem with the wiper switch.

ignition off -> darkblue(0V), yellow(0V)
ignition on/wiper switch out -> darkblue(0V), yellow(12V)
ignition on wiper switch in -> darkblue(0V), yellow(12V)

I was thinking the darkblue should change voltage depending on the washer switch position ?

Thanks

[etg]

This is the wiring according to a shop manual.

http://67-72chevytrucks.com/vboard/a...1&d=1287705190

This is the thread I got it from. There is a complete colored wiring diagram in this thread and around the board, that was the only problem on it though.

http://67-72chevytrucks.com/vboard/s...=185856&page=8

When you get it to work, please post pictures of your success. I followed this wiring diagram, reran wires, replaced the motor even though both bench tested fine, and I still can't get mine to work. It doesn't usually rain in SD, but it is now and I can't drive without my wipers!

[mightyatom]

Many thanks.
The shop manual seems a lot clearer than the FAQ color wiring diagrams with regard to which connections are for the washer pump. The shop manual diagram shows it should be lightblue/yellow going to the washer, with darkblue/yellow/black going to the wiper motor.
According to the diagram my lightblue and darkblue wire are transposed if I am reading it correctly.

The FAQ electrical diagram just shows all the wires going to a single wiper/washer unit so its difficult to know which wires are for the washer pump.

Can anyone post a photo or describe the connections for their working washer pump ?

Thanks

[etg]

I had the same problem deciphering which wires go where. Here is a picture of an installed wiper motor I took at a junkyard. No real way of knowing if it was right, but I have seen at least 2 trucks wired this way so I assume it is.




What I could not find is a ground strop under any of the rubber grommet pad things. If you click on the image you can see yellow on bottom, then light blue, then black. I think that's on the wiper motor. For the washer you have dark blue on top, and 2 yellow on bottom.

Hope this helps, lemme know if it works out.

[mightyatom]

That helps a lot. It is wired exactly like mine is so I think my wiring is probably correct. I guess I will replace the pump and see if it helps.

Many thanks for the photo.

[etg]

No problem, here is a thread that will help you test the motor once you've pulled it.

http://67-72chevytrucks.com/vboard/s...d.php?t=413551

[VetteVet]

Originally Posted by mightyatom

Many thanks.
The shop manual seems a lot clearer than the FAQ color wiring diagrams with regard to which connections are for the washer pump. The shop manual diagram shows it should be lightblue/yellow going to the washer, with darkblue/yellow/black going to the wiper motor.
According to the diagram my lightblue and darkblue wire are transposed if I am reading it correctly.

The FAQ electrical diagram just shows all the wires going to a single wiper/washer unit so its difficult to know which wires are for the washer pump.

Can anyone post a photo or describe the connections for their working washer pump ?

Thanks

The wiring in this diagram is incorrect. The yellow wire does not connect with the black wire as this will create a dead short when the pump is selected. The black wire should go on the terminal in the middle. Whoever drew the diagram made a mistake and the shop manual shows it plainly. The diagram below shows this.


This is the incorrect diagram



This is from the shop manual and is correct. The motor itself still has to be grounded in order to provide a path to ground for the wiper switch wires and the motor speed windings. All the wires that go to the wiper motor/washer switch are ground wires and no voltage should be present at the switch.

[mightyatom]

So am I correct in saying the following:
1. that the lightblue/yellow connections at the top of the shop manual diagram are the wires that should be going to the washer pump. If so mine is wired incorrectly as I have the darkblue going to the washer pump and the lightblue to the wiper motor. The posted photo's in the previous reply also have the incorrect wiring.
2. the washer will have two wires, a yellow (12V switched from ignition) wire and a lightblue wire from the wiper switch (GND) when washer activated and floating or 12V when washer NOT activated.

Sorry to keep going on this but at $30 for a wiper switch or washer pump I would like to hopefully change only the fault component and not both.

Many Thanks

[VetteVet]

You should keep going until you get the answer you need. I did a search on the forum and found a thread that may help or add to the confusion. It has a post in it by Putter that describes what each wire does so I copied it for you. He is a sharp guy so I believe he is right. I haven't found another post to confirm his description.

Now, you can find out which wire does what by grounding it at the motor and seeing what happens. You can do this at the wiper switch if you can get to it but if there is a break in the wire anywhere the wiper motor won't work. I suspect you have a bad switch but we'll run through it anyway.

Now you know that the yellow wire is hot whenever the key is on and you have confirmed that in one of your posts above.
According to Putter the black wire is the low speed switch wire so if you ground it the wipers should run on low speed.

The light blue wire is high speed, BUT, the light blue wire and the black wire both have to be grounded for the high speed to work. I forgot about that.

The dark blue wire is the washer motor wire, but all it actually does is activate a solenoid so that the motor lobe on low speed works a pump in the washer. to do this the wiper switch when pushed in grounds the dark blue wire and the black wire to the motor. This was explained by dsy 1 in this thread.

SO if you hear the motor running and the washer solenoid clicking, the pump should be pumping fluid if the tank has fluid and the hose is good and the pump seals are good.

The below is from Putter's post.






Re: wiper motor wiring
(See photo below)


Wiper switch plug:
Black wire = low speed
Dark blue (center) wire = wash
Light blue wire = high speed

The wiper switch wires are ground wires. If you remove the switch and simply jump them to ground, it will make each function work.
**NOTE - for high speed, you have to ground BOTH light blue & black at the same time.

Wiper motor plug:
Yellow wires are hot. One goes to fuse box and the other goes to the other terminal on the wiper motor. (see photo)
Dark blue wire connects directly to the dark blue wire on the switch plug.

( WIPER MOTOR PLUG):
Yellow wire - jumps around to the other yellow wiper motor plug. (see photo)
Light blue wire - connects directly to the light blue wire on the switch plug.

( WIPER MOTOR PLUG #2):
single black wire - connects directly to the black wire on the switch plug.

[mightyatom]

Many thanks for the details it helped a lot. I made sure I have the correct voltages and decided it was the pump so switched it out. Now my washer is working for the first time since I bought the truck. Also managed to get my heater/fan and original radio working over the xmas holidays so I am a happy camper.
I have got to say that this is the most helpful forum I have ever encountered, awesome...

[Akleypas]

I had an issue where my washer pump would squirt out some bug juice when just the wipers were running. I thought maybe it was a wiring issue. I noticed however that when I would activate the washer pump the bug juice would squirt out a lot more voraciously. The issue was that the pump arm ( oscillates the diaphragm of the pump) was a little short and was being slightly engaged during normal function of the wiper motor. I pulled the pump off and used a file to shorten the pump arm and now my wipers and washer pump are working as intended.

[Accelo]

Sometimes a syringe can be helpful to prime the system. I like to use soap in the water as it helps lubricate the pump. If you don't have a syringe pulling the hose back through the fender and holding the reservoir above the pump helps.

[1970cstblazer]

https://www.napaonline.com/en/p/WIP6300



After issue after issue with the original style NOS Delco pumps, I went with this on demand type pump on my 1970 Blazer. I completely removed the original pump from the wiper motor. I mounted the new NAPA pump on the steel accelerator pedal bracket after drilling a couple of holes. My Blazer has the 1971-72 style cable throttle control. Older trucks will need to have a different mounting location. I added blade style connectors to the new NAPA pumps wire leads, and plugged them into the original plug, so no mods to the original wiring harness. This new pump shoots a large amount of fluid, and everything appears stock.

[PbFut]

Why not put the pump in the engine bay and run a single wire to the pump. Change the grommet to a single wire type and get the rubber hoses out of the firewall passage. This will reduce the chance of the fire traveling with the rubber hoses into the insulation in the cab. Ask me how I now

[1970cstblazer]

That is a good point. Never gave that a thought. My emphasis with this modification was factory stock appearance.