Here is the scoop. The headlights work great. The wiper door does nothing when I put the wiper switch on. When I pull the override control by the pedals the wiper door will open, and then will close when I push the override back in. When I have the wiper door open, and put the wiper switch on, nothing happens.

Can anyone help on my first step to solving?
Thanks!!

 

1st step go to Willcox and search around.

http://willcoxcorvette.com/repairand...787f158a0c40dd


You will find all sorts of trouble shooting help from this vendor unlike most that just want to sell you the parts.

Here's a few dealing with your 68, there might be more so check the link above too.

http://willcoxcorvette.com/repairand...lp.php?hID=218

http://willcoxcorvette.com/repairand...lp.php?hID=195

http://willcoxcorvette.com/repairand...lp.php?hID=201

 

Sounds like an electrical problem. Id first ohm out the switch, and check for voltage there. If its there, check the voltage at the motor.

You have check for the lock out switch not being on (the round **** next to the override switch)?

 

when you open the door with the over ride will the wipers then come on?

 

CDogzr:

Have you tested the Tach solenoid? This is what controls the vacuum to the wiper door relay on 68 only. It shuts off vacuum to this relay which makes the door open. (This is what you are doing when you pull the override vacuum switch ****). To test this solenoid, go to the link DZ posted above (218) it will show you.

Test the limit switch at the firewall! The plunger is controlled by the wiper door linkage and if this switch is not collapsed the motor will not run. You can test this by checking to see if voltage is passing through when it is closed. (door open).

But the problem with your wiper cover door seems to be something to do with the solenoid if the override is working the door just fine.

I think after this I would do is make sure you don’t have the motor override switch turned off. I know you probably did but you would not imagine how many times cars have been fixed quickly from a new owner not knowing the function of the switch.

Then I would upload the manual test (number 195) listed above in DZ’s post. (Thanks for the kind words DZ)

You can do this on the car but make sure to un-plug all wires from your motor first and have that wiper door open. If this test works then you can eliminate the motor as the problem.

Just a note to: I will need to check that schematic. The 69-72 schematic we had posted for a long time had an issue at the relay with the black wire with the white stripe being in the wrong place. It was correct in Jan. but I never thought to check this one. It is possible that the OE GM schematic was wrong (on the 68 schematic from GM there are four mistakes that I know of besides this one) and the GM schematic is what we used when we drew up the one on that page.

I just looked at it and I’m pretty sure it is wrong. I believe the Black wire with a white stripe runs back to the wiper switch and the solid black wire runs to ground.

Boy. . . 68 is the hardest year to work on that is for sure. You have two problems here, one is the door the other is the motor so you might want to do one first and then move forward.

Willcox Inc.

 

Dear Wilcox, I have some more info. The three prong plug by the wiper was not connected. When I connect this and then move the wiper switch to on, the cowl door opens and the wipers come on. The high and low speed work fine. When I turn the switch off the wipers go down, but do not complete seat, they sit in the ready position. I did gently push them down and then gently pushed the cowl down into place. So....they do kinda work, put are not seated. I have not yet tested the tach solenoid. Any other thoughts...or still test the tach solenoid? One more question, what is the turn switch for that is located by the vacuum override controls under the dash for?

Thanks so much for a response.

 

Cdogzr-

I've been out of town and my internet access to say the least. . . Sucked!

It sounds to me as if the arms are not parking completely.

I would first go to the page on wiper arm adjustment. This may solve both your problems. The arms have to be down for the door to close.

The switch in-between the two vacuum switches is the motor over-ride switch. It will turn off power to the wiper motor and allow you to change the wiper blades.

You don’t need to test the solenoid, it’s working or the wipers would not be!

Willcox Inc.

 

Sorry to highjack the thread but figured it was better than starting a new one. Gotta say the info on the Wilcox site is extremely helpful.

I'm having trouble with my 71 and narrowed it down to the wiper switch on the dash earthing out in the off position.

I have trouble understanding why the solenoid to open the door is only on the high speed. If I earth low speed at the switch (black/white), wiper door won't open unless the wiper moves off the vacuum switch, but ground high speed and the vac solenoid operates opening the door. Seems silly - shouldn't the vac solenoid open on low and high speeds?

Wiper motor is out of the car but earthing the wire at the dash switch, I get switched ground on the Lgreen at the motor connector on low speed, and switched ground at Lgreen and Lblue at the motor on high speed - that's normal (I think).

If I connect the old dash switch I get earth in the off position and no earth in high speed position so I figure I need a new one.

Wiper motor runs (out of car) if power is to the wire connecting the limit switch and the motor body is earthed. If I just put power to the middle pin and earth to the pin to its left (low speed) the solenoid clicks but nothing happens - I figure I need a new motor as well?

Any help greatly appreciated!!

 

Chris,

I just saw this post, did you figure it out yet? Post again and if not, I'll take a look at this for you.

Willcox

 

Wilcox, I did readjust the wipers and got them to work OK....I did spray all of the moving parts for the cowl and now it does come back down after about 10 seconds....slowly....but I anticipte this to get better.

Thanks for the help.

Cdogzr

 

Bad wiper switch or bad solenoid on the back of the tach.

Bad wiper switch or bad limit switch on the cowl.

Opening and closing the wiper door is 100% vacuum. Operation of the wipers is 100% electrical.

Activating the wiper switch on the dash sends an electrical signal to the solenoid on the back of the tach. The solenoid then sends a vacuum signal to open the wiper door. As the wiper door nears full open, a pluger on the hinge hardware trips the limit switch. Limit switch turns on the wipers as the wiper door parks in full open. Here's the limit switch on the cowl:



I'm thinking you've got a bad wiper switch.

 

Glad you got it working! You might need to keep spaying it and over time it will probably get better. You may want to consider replacement of the bushings. Oh. . . Don't forget there are pivot areas on the underside the door pivots on the linkage and it is hard to reach, make sure you spray in this area.

Willcox