Just got the car so I’m trying things out... I turned on the wipers and the door opened, whippers came on. Low and high speed work, the washer didn’t squirt but the fluid bag was empty. When I turned off the whippers they retracted but the door didn’t close. I don’t see any vacuum tubes disconnected but I’m not sure where to look either. I was also playing with the switches under the steering wheel but with no luck. I also included a pic of some rubber tubes coming out of the passenger side fire wall and there is one that seems to be cut or not connected to anything. When the motor is running there is no vacuum in that tube though. Any insight on what the problem could be is appreciated.

 

The one you see that looks cut, that is normal. There are numerous switches and vacuum lines in the system. Do a search and you will find it has all been covered. To make a diagnosis without being there won't work.

 

Check the wiper door over ride. You owner's manual explains it. The hose under the hood with nothing connected to it is a vent.

 

You mean the big black **** in the middle? I tried pushing it up but it won’t go up. It turns clockwise or counter clockwise which enable or disables the whippers. The lever to the left of it opens and closes the head lights. The lever to the right turns on and off the whippers so you can access them to change the whipper blades.

I think my problem lies somewhere else. Going to have another look at it tomorrow with a mechanic but he is not a Corvette guy...

 

Theres a switch in the wiper bay that tells the door that the wipers are at rest. That could be bad.

 

Its kinda hard to see in there, when the door is up there’s not that much room. Can you be more specific where the switch is? Thanks for the help 👍🏻

 

I repaired mine by replacing a faulty wiper arm relay. Check Willcox videos for a proper test of one. This video will also help you out.......

 

R/S right by where the wiper arm lays. I had the same problem when O bought my 72. I replaced everything related to the wiper door.

 

Great video thanks for that...👍🏻 Will check tomorrow

 

Do not give a mechanic money to learn about corvettes. That would get expensive fast. Invest in a vacuum testor like a mighty vac and spend some time here reading, reseaching and asking questions. I agree diagnosing 2nd hand is difficult but you"ll be a bit happier with the result. You already know you have both vacuum signals going to the actuator because the door openned when you turned on the wipers.

the first signal is the OPEN vacuum that comes from the electrical signal to the vacuum relay under the dash, that gives vacuum to the actuator relay in the fendor well that switches vacuum to the door open side of the wiper door actuator. The second Vacuum is the vacuum that actually does the work of openning and closing the door. When you switch it to off the signal shuts off to the actuator relay and that relay moves to the close position and vacuum goes to the close side of the actuator.

So the actuator relay is either leaking, stuck or disconnected, or the actuator is stuck or leaking on that side. You said the hose on the close side has no vacuum so trace it into the fender and see if its connected. You can take the vacuum line that supplies the actuator and see if it has vacuum then put that directly to thte close side of the actuator and see ifit will close to trouble shoot the can itself. But usually if the vacuum opens it , it will close it since both sides share the same diapram.

Willcox has some good trouble shooting schematics and you are not the first person with this problem so you should be able to find the answerr

 

Please include the year of your vette so we can have a bit more information to help you. the 68 system which I am more familiar with is slightly different from the 69 and later models.

http://repairs.willcoxcorvette.com/w...-schematic.jpg

http://repairs.willcoxcorvette.com/w...ic-69-late.jpg

And a helpful idea is to put a white mark on the wiper override switch **** under the dash that turns. With the wipers on and working, put a white mark on that **** so you can easily see if it is turned. I have bumper that switch more than once shutting off the wiper system and not realizing it.

 

I have a 71 coupe. Was working on it today and was able to get the whipper door to close by manually closing it, just pushing it down. Now when I shut off the motor the door opens... I’m going to replace the vacuum valves which should solve the problem, I hope...

 

I fixed it...😎 The vídeo from Wilcox was a great help, thanks for that. As it turns out it was the whipper door activator safety switch. I’m including a pic of the bad switch and a diagram of the vacuum system I downloaded from Wilcox and a trouble shooting guide I got from Ecklers.

Just to to recap what was happening. As soon as I started the engine the whipper door would open up and stay there... I guess it’s a very common problem and an easy fix once you know what’s going on.

 

That's great that you got the wiper door to work correctly, it's a somewhat unique cool system when it works. I remember getting mine to work, was very satisfying.