Corvette Forum : DigitalCorvettes.com Corvette Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
49 Posts
Discussion Starter · #1 ·
Hi everyone. I'm Matt and I'm new here. I made a thread in the 'Intro and Greets' section. I recently bought my dream car - a chrome bumper big block Corvette. It's a great car, but I want to fix a few things up on it.

My wipers and vacuum system work well. Excellently in fact. However, the washers do not work. I've looked under the hood, and the washer pump has been attacked by Bubba. It has no cover, springs are missing, etc. I think I'll just buy a new one, although this is harder for me in that I live in Australia!

I've done some searching, but I haven't come up with the answer to this. It's a total noob question, but here goes. On a '71 Corvette, if the wipers are off (switch over to far left), and I push the Washer button, what should happen?

Should the wiper panel pop open, the wipers cycle and the washers work for a few cycles, then the panel pops closed? Or do the washers only work if the wipers are in 'Lo' or 'Hi' speed already?

Cheers and regards,
Matt.
 

·
Registered
Joined
·
607 Posts
Hi Matt,

Welcome to the forum and congrats on the new Vette.

I cant really answer your question as my car doesn't have the wiper door and my washers don't work anyway:down:


But heres a friendly bump to the top:thumbsup:





Liam.
 

·
Registered
Joined
·
2,002 Posts
...On a '71 Corvette, if the wipers are off (switch over to far left), and I push the Washer button, what should happen?...Should the wiper panel pop open, the wipers cycle and the washers work for a few cycles, then the panel pops closed?...
I believe that is correct. Do you have an owner's manual? If memory serves, washer function is explained in my 68 owner's manual and I would assume 71 would be the same.

You will need the 71 assembly instruction manual (AIM), GM chassis service manual, or a wiring diagram to determine the correct number of wires to the wiper motor connection under the hood. It's a molded plug coming off of the engine harness.

:thumbsup:
 

·
Registered
Joined
·
5,206 Posts
I haven't looked at my brother '69 in a while, but its washer system is very simular to my '74.

Corvette windscreen squirter "pulse" the spray as in not a steady stream when operated.

On the front of the black plasitic cover on the center of the wiper motor (facing the engine) there should be (2) wires that plug into the cover oposite of each other.

In other words, one wire plugs into the wiper cover on the driver side parallel to the fire wall and another wire plugs into the cover from the passenger side parrael to the fire wall. One wire is hot when you push the wash button, the other is ground and is looped back to the wiper motor connections (the 4 wire plug on the wiper motor)

These two wire operate a solenoid that turns into a magnet. The magnet makes the washer pump arm engage the spinning cam gear that is directly connected to the wiper motor. the cam is made that after one revolution with the pump arm in contact reset the pump arm in its resting position. its kinda a complicated peice of machinery if you get my drift :WTF

For touble shooting purpose you can un plug the two wires, remove the cover and re-attach the wires. put a little water on the wind screen (so not to scratch or over work the wiper motor)and have a helper push the wiper /wash button. The pump arm should get "picked up" by the magnet and dropped on the rotating cam producing a in and out motion of the pump and after one revolution it should mechaniclly place the arm back in the 'park" position. If it does this there is nothing wrong electrically.

Now if the arm is always in contact with the cam and has none or very little "in and out motion", then then cam is worn and needs replacment. If the pump is activated and nothing squirts then either your pump seals are dried out and need replacment or the steel nossels attached to the wiper arms are plugged. I know this is lot but I could say it any shorter, hope it helps

BTW you should be able to buy the parts you need to rebuild on the internet (Mid America, Paragon, Corvette America)
 

·
Registered
Joined
·
49 Posts
Discussion Starter · #6 ·
These two wire operate a solenoid that turns into a magnet. The magnet makes the washer pump arm engage the spinning cam gear that is directly connected to the wiper motor. the cam is made that after one revolution with the pump arm in contact reset the pump arm in its resting position. its kinda a complicated piece of machinery if you get my drift :WTF

For trouble shooting purpose you can unplug the two wires, remove the cover and re-attach the wires. put a little water on the wind screen (so not to scratch or over work the wiper motor)and have a helper push the wiper /wash button. The pump arm should get "picked up" by the magnet and dropped on the rotating cam producing a in and out motion of the pump and after one revolution it should mechaniclly place the arm back in the 'park" position. If it does this there is nothing wrong electrically.

Now if the arm is always in contact with the cam and has none or very little "in and out motion", then then cam is worn and needs replacment. If the pump is activated and nothing squirts then either your pump seals are dried out and need replacment or the steel nossels attached to the wiper arms are plugged. I know this is lot but I could say it any shorter, hope it helps

BTW you should be able to buy the parts you need to rebuild on the internet (Mid America, Paragon, Corvette America)
You are too much mate. Thank you very much.

I think I do get it. Here is my interpretation. When you push the washer button in, it momentarily energizes the solenoid. This solenoid is an electromagnet, which attracts the metal of the pump arm. Letting go of the washer button collapses the magnetic field in the solenoid, thus letting go of the pump arm. The pump arm, no longer attracted to the solenoid falls down and lands on the the cam and cycles the diaphragm until the cam reaches a complete revolution whereby the pump arm parks, ready to be picked up again by pushing the washer button.

The other part I don't get. When I push the button in, how are the wiper arms themselves triggered? Does pushing the washer button in also move the button to the left into the 'Lo' speed setting? That is, all the washer button mechanically moves the wiper witch into 'Lo' and electrically energizes the solenoid? Or are there additional wires that turn on the wiper motor as well?

Thank you so much mate!
Matt.
 

·
Registered
Joined
·
49 Posts
Discussion Starter · #7 ·
I got to go out and play with the car and worked out that the switch does indeed move over to the 'Lo' position. It's actually devilishly simple in concept.

Now I know why it doesn't work though. Bubba has removed most of the internals of the pump! I have no idea where the wires are gone either!
 

·
Registered
Joined
·
2,002 Posts
Purchase the assembly instruction manual (AIM). The AIM has diagrams of how the pump was installed, wired, where the wires come from, and the various ins and outs of pump hose routing.

:thumbsup:
 
1 - 9 of 9 Posts
Top