I have a 72. My wiper door panel is stuck in the open position. When I move my wiper switch from off to high, nothing happens, but when I push it in for washer fluid, the wipers turn on (move).

I am assuming that the wiper motor is working if the blades move. Am I correct? Could the switch be bad? When we put a volt meter up to it, it shows continuity between the middle and right posts but not the left (the off position???) but the only time anything happens is when the switch is pushed in.

Could the relay valve be bad?

Anyone else struggling with this or know what I can do to fix it? I don't want to just replace a bunch of parts hoping to find the problem.

Thanks, Bridget

 

Hi Bridget,
The wipers work normally on/off, but the door stays open?
Or do the wipers continue to run when you turn the switch off?
When you turn the wipers off are they returning to the park (fully down against the stop bracket the blades rest on) position?
If they are, have you checked the wiper door override switch below the steering column.
If this switch has been pulled down the door stays open under all conditions.
So, a couple of questions and something to check!
Regards,
Alan

Make sure this shaft is pushed UP.

 

And check out WILLCOX Corvette-- they have a great troubleshooting write-up on the wiper system- both the vacuum side and the electric side.

 

Saves a lot of time trying it all out on what can be wrong....when WiLLCOX has done it for those who need it.

DUB

 

Thanks for your reply. No the wipers do not work unless I push in the fluid button. Then they go once. The door has never been closed as long as I've had the car. This car was A basket case when I got it. I don't even know if all the pieces are here for this door to work. I'm going to try to add some pictures. Maybe someone can tell if I'

m missing parts.








Is this hose supposed to be connected to anything?



Is anything supposed to be on this bracket?

 

Hi B,
I take a couple of the easy ones first:
The small hose coming through the right side firewall near the hood latch is the 'vent' for the wiper door safety switch in the right side of the wiper bay. It doesn't connect to any thing.
The small plate on the right side apron supports a clip for the heater hoses. It's the same clip as shown in the photo of the wiper door actuator.

It appears all the parts are there (except that we can't see if the wiper door solenoid that's mounted to the rear of the case for the tach is there, or the wiper door relay mounted on the rear of the right-side apron.)

The wiper system has both electrical components and vacuum operated components. We need to begin to separate them so you can begin to test them individually.
Do you have a 72 Assembly Instruction Manual (AIM)? Do you have the 72 Chassis Service Manual? Do you have any sort of 'trouble shooting guide for the wiper system? Do you have a vacuum pump with a gauge (like a mity-vac)? Do you have a small electrical multi-tester? Knowing what you have to refer to and use will help someone guide you through the trouble shooting process. It's likely that it's more than just one component causing your problems.

Do your headlights work? This will indicate that at least the vacuum from the engine is entering the system.

Regards,
Alan

The wiper door solenoid.


The wiper door vacuum relay.

 

Sorry for posting the same stuff as last time.. but I'm on the upper east coast killing lobsters for three weeks...

Video on testing the motor:
1969-1972


Video on testing the switch


Wiper Motor Bench Test 69-72


1969-1976 Corvette Wiper Motor Bench Testing and Some Relay Repair Help


Ohhhhhh sooooo Free Simple schematic.



The following should help you understand how to test most of the items in your system.
69-72 Wiper Arm Vacuum Relay testing.


1968-1982 Corvette Headlamp and Wiper Vacuum Diagnostic Help.










Willcox-
18243

 

Is there a way for me to see the solenoid without taking apart the dash?

I found the relay and it has it's three hoses attached.

Yes, I have the assembly manual, a repair manual and a service manual. I also have a mity-vac and a volt meter. We tested the actuator valve today and it held at about 5 lbs. but we didn't go any higher because we didn't know how much pressure it could handle.

Yes my headlights work.

(I really should be working on putting in my carpet, but this puzzle has me consumed!)


Thanks everyone. I am going to check out Willcox now.

 

[QUOTE=bchochole;1595033056]Is there a way for me to see the solenoid without taking apart the dash?

I found the relay and it has it's three hoses attached.

Yes, I have the assembly manual, a repair manual and a service manual. I also have a mity-vac and a volt meter. We tested the actuator valve today and it held at about 5 lbs. but we didn't go any higher because we didn't know how much pressure it could handle.

Yes my headlights work.

(I really should be working on putting in my carpet, but this puzzle has me consumed!)

I'm sorry, I edited my post above and humbly forgot to post the vacuum diagram.



If you go to the over-ride switch with the wipers turned on... if the solenoid is working it will block vacuum on the black with a blue stripe hose... the nipple closest to the override **** in the picture above... You should have vacuum on this hose with the wipers off, and should not have vacuum on it with the wipers on.... this is controlled by the solenoid in the picture. Post back.. I'll try to check in... but where I'm staying for the next three weeks has horrible internet... Damn villages in Maine have funny rules...

 

Pull the cover and the switch out without unplugging it and take a picture of the plug installed. If the wipers never worked since you got it then I would suspect that someone plugged the switch in backwards. Weird things happen when this sytem isnt wire correctly

 

You have two systems in play here-

Do NOT worry about the vacuum system TILL you have the wipers operational electrically. OTHERWISE- you'll be overwhelmed and chasing your tail.

Opening the door manually (or as you said always open) and try to get park/low/high working. Just disconnect the vacuum canister for right now.

What's known-

For the wipers to 'move' at all- requires

1)12v ignition at the yellow wire ( in three spade connector)

2) you have a constant 12v at the wiper motor -running directly to the side of the motor via a single wire. This power goes through the service switch under the dash- to the switch on the firewall then to the wiper motor.
3) The solenoid behind the dash is NOT your problem as far as running the wipers- but could be a problem for the door not being operational (DON'T worry about it now)

4)And you have a ground at some point.(motor test will determine)

The park-low- high speeds are controlled by a combinations of grounds and a shunt (AKA a resistor)- NOT positive switching- You have to have power at two places on the motor for it to operate at all- since it operates-you have power at BOTH places!

You have either -the switch- wiper relay under the dash or the wiper motor itself (shunt and or internal solenoid) that can cause your problem.

I'd start by checking the motor first via the Willcox video - then the switch and lastly the relay in the dash.

BTW - I have a box of extra parts off my car( 71OEM) that have been tested. Since I converted mine to a newer GM style with delayed/intermittent controls and not going to need the original stuff

Richard

 

Hi Bridget,

"Is there a way for me to see the solenoid without taking apart the dash?"

Yes. It's difficult but if you get your head down below the dash pad you can see and reach the solenoid since it's mounted quite low on the tach housing. Unless you have the body of a 10 year old it's easiest to reach it with the seat out.
Check both it's electrical and vacuum functions.

"I found the relay and it has it's three hoses attached."

The relay should have 4 hoses attached to it. A small 'control' hose at the 'pipe' coming out of the metal 'can' and 3 large 'servo' hoses (one large yellow stripe, a large green stripe and a large red stripe).

Regards,
Alan

 

I am waiting to comment further til she goes through all the information that WILLCOX provided.

I DO agree with 'Richard454'. get the wiper motor working first and then the vacuum.

DUB

 

If she uses the technique I posted above there is no reason to view the solenoid. It will tell her if the solenoid is working properly or not. If not, then go looking for the solenoid..

Willcox

 

still think the switch is in backwards. look at the schematic, pushing in the washer switch and the wipers cycle.

 

Could be.. easy to find out! Just pop out the wiper switch plate, snap a picture and post it.

Ernie

 

WILLCOX,

I am SO GLAD that you posted all of the tests and so on ...it simply saves many of us who also know this stuff from having to type out what you have kindly provided.

My 'hats' off to you for doing that!

DUB

 

I think you're right.

To test without taking the interior apart, Bridget, try pressing and holding the washer switch. If it continues to run more than once, then you've found the issue.