J Mo

After car is started in a minute or two wiper door rises and stays up. all lines have been replaced as well as switch under fender. I can get door to go down at times depressing switch that wipers rest on. but when restarting the door opens again??? At a loss.... Any one have any clues ??? Or anyone know anybody in the Philly area that knows the vacuum systems ??? Help !!!!

Thanks

John

Dave J

John;

You can do a very simple test. Remove the wiper grill. Remove the middle and lower vacuum hoses off the valve under the passenger wiper arm and connect them together. You have effectively bypassed the valve. If that is your problem, the door should stay down.

J Mo

Thanks Dave, will give it a try !

0Willcox Corvette

Dave... you keep this "wiper door diagnostics" up... I'm gonna pass the wiper motor issue to you too.. lol.. In the last week, I've had 12 emails about the wiper motors... I can't answer them fast enough.

E

J Mo

Hi Dave, tried bypassing the switch and no luck. Any other steps to try to fix the door ? Also wanted to add that the the lights also pop up and then drop back down when I start the car also. Seems like the headlights pop up , then go back down then the wiper door opens,


John

Dave J

Hey John,

I am out in the wilds of western Nebraska on vacation Walleye fishing. You need extensive testing of all control circuit components. Can you wait till after I return (June 11th)? I have no cell service or anything else here, I'm only in a local town now to buy more beer.

J Mo

Hi Dave,

I can wait, I'd rather try to trouble shoot myself first before paying someone to do it . Enjoy you fishing ! Ever try using Walleye fish guts as bait ???

0Willcox Corvette

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-

J Mo

If you were close I'd bring my car to you and have you fix it !!!

mrvette

I"m so happy I changed over to electric operation on my wiper door, and ditched the headlights....(not MY decision on that one, it was decided by a damn deer into both headlights one night, gave the car a new look, you know that stare....deer in the headlights??

V4motorsports

Willcox has some great videos but maybe this one can help you also:


Good luck, between the Willcox videos and this one, I have both my wiper door and headlights working like new!

Russ

J Mo

Hi Russ,
Thanks for the video, I have already ordered filter and check valve and wiper switch. So hopefully I am on the right track and this takes care of the issue ! Thanks again !

John

J Mo

Hi Russ,

Installed check valve and filter and thee was no change with the issue of wiper door and headlights. Any other suggestions ???

John

Dave J

John, It looks like you need more involved testing before you can determine exactly is wrong. Do you have a vacuum pump like a Mityvac, or even a vacuum gauge?

btw, walleye guts can only work when you have walleyes to clean..........

Alan 71

Hi John,
In trying to trouble shoot wiper door/head light door problems it some times helps to have a basic understanding of the concepts behind the system.
I wrote this to be included in another thread.

You describe what some people have called a 'dancing' wiper door and 'winking' headlights.

The vacuum systems for the headlights and wiper door have 2 'sides'.

The 'servo' side is the part of the system that actually moves the doors.
It consists of the actuators, the large hoses, and the storage tank.
The 'control' side of the system determines which side of the actuator ('open'...green hose or 'close'…red hose) receives the vacuum and consists of the switch (for headlights), relays, safety switch and solenoid (for wiper door), and small hoses.

The system is designed to be 'biased' to the 'control' side….
at start up the 'control' should receive full operating vacuum FIRST and thus 'send' the signal to the actuators (servo side) to remain where they are.
If that doesn't happen the 'actuators' receive full vacuum FIRST and open the door (wiper door and/or headlight doors) until the 'control' side relay signals them to close again.
This is because the 'fail' condition for the system is for the doors to open.

The control side of the wiper door system is failing so the door opens and stays open
For the wiper door look for a leak at the:
check valve (sounds like you have already)
filter (sounds like you have already)
wiper door relay
small hoses
wiper vacuum over-ride switch.
'close' side of the door actuator (large red striped hose, pipe faces front of car)

Have you checked the wiper door vacuum over-ride and it's hoses located below the steering column?
Have you checked the wiper door relay and it's hose connections to the door actuator?
Regards,
Alan

Relay


Red hose (from relay) at front of actuator


Hoses to/from vacuum safety switch.


Hoses at the vacuum safety switch.

J Mo

Hi Alan,

I have replaced the relay under the passenger fender, connected the middle and bottom hoses to by-pass the wiper down switch with not luck. In reference to wiper door relay and it's hose connections to the door actuator, besides making sure they are connected, is there a way to check actuator to insure that it's working correctly ?

Thanks,
John

Alan 71

Hi John,
The wiper (and headlight) actuator is easy to test.

First block the nipple on the side of the actuator that the arm comes out of. Connect your pump to the other nipple. IF the vacuum holds, the plenum seal in the actuator is good. If it doesn't, the actuator needs to be un-crimped to replace the plenum seal…. not easy to do.

Then block the other nipple and connect the pump to the nipple on the side of the actuator with the rod. If the vacuum holds, the actuator is good. If the vacuum leaks down the small seal on the rod needs to be replaced. This is an easy job.
Good Luck!
Regards,
Alan