'70 Corvette Wiper Problem.
Thread Starter
Drifting
Joined: Feb 2000
Posts: 1,591
Likes: 53
From: Central MN
'70 Corvette Wiper Problem.
I am running into a problem with the wiper door not opening on my '70 Corvette. Basically, the wiper door will not open when I turn the wipers on or pull down on the over ride switch. If I manually open the door, (remove the rubber plug from the actuator and push the plunger with my thumb) the wipers come on and operate normally. At this point, I've replaced the wiper arm vacuum relay (the old one was terribly corroded.) The headlights, by the way, work perfectly. Any ideas??? Thanks.
Safety Car
Joined: Feb 2006
Posts: 3,557
Likes: 0
From: Ridgeway VA
Make sure the rubber plug does not leak, make sure hoses are not blocking the door from opening, make sure the drivers wiper arm fits down first then make sure the RH wiper actually does seat on the top of that relay -if not the wiper arm needs adjustment. Also, check under the dash for loose hoses especially the hoses that go to the solenoid.
Safety Car
Joined: Aug 2001
Posts: 4,883
Likes: 11
From: North Easton Mass
If you have the bellows-like cover over the wiper door shaft, pull it back and make sure the seal around the wiper door rod is in place. The wipers on my 72 didn't work the first time I tried them, and I found that the seal had popped out of the vacuum can. I put it back in and the door has worked since then.
Rick B.
Rick B.
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
Something is telling the door not to open and I'm betting on the interlock switch under the passenger side wiper arm.
If you remove the wiper grille you can slip a screwdriver between the wiper transmission arm and the switch contact button and press down on it and see if the door opens.
The previously mentioned seal is also a good thing to check. It is on the rod that comes out from the wiper actuator toward the passenger compartment. If the seal has been pulled out there is a good chance you need to adjust your wiper actuator rod so the adjustment nuts don't hit the seal during opening and closing.
cc
If you remove the wiper grille you can slip a screwdriver between the wiper transmission arm and the switch contact button and press down on it and see if the door opens.
The previously mentioned seal is also a good thing to check. It is on the rod that comes out from the wiper actuator toward the passenger compartment. If the seal has been pulled out there is a good chance you need to adjust your wiper actuator rod so the adjustment nuts don't hit the seal during opening and closing.
cc
Pro
Joined: Mar 2004
Posts: 640
Likes: 1
From: Mertztown Pa
Did you replace the actuator? If that is what you were talking about I would have to say it would be the relay. It would have one small vacuum tube and 3 larger tubes coming out of it. If it don't open with the override then I wouls say it has to be that.
Pro
Joined: Mar 2004
Posts: 640
Likes: 1
From: Mertztown Pa
If you did not replace this:
http://www.corvette-paragon.com/p-35...lay-valve.aspx
This is what I was talking about.
http://www.corvette-paragon.com/p-35...lay-valve.aspx
This is what I was talking about.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
With the engine running remove the 1 small hose from the relay (pictured in the above link) if the wiper door pops up then your problem is as CCrane says in the control side of the vacuum system.
Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
Think of the vacuum relay as an electric relay. If there is vacuum on the small hose that DWncchs mentioned, the relay should apply vacuum to the back side of the actuator. When vacuum is removed by a.) removing the hose, b.) pulling the manual override down, or c.) turning the wiper switch on, the diaphragm in the relay will move down by spring pressure, applying vacuum to the front side of the actuator, which in turn opens the door.
Given the above, you can check the hoses going to the actuator and see if you are getting vacuum to the front and rear sides of the actuator.
Hey, your Z is almost a twin of mine, and our C3s are only a year apart!
Given the above, you can check the hoses going to the actuator and see if you are getting vacuum to the front and rear sides of the actuator.
Hey, your Z is almost a twin of mine, and our C3s are only a year apart!
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Thread Starter
Drifting
Joined: Feb 2000
Posts: 1,591
Likes: 53
From: Central MN
Everybody...........Thanks for all your input and suggestions. Upon researching old threads, I came across this hyperlink from Willcox Corvette:
http://willcoxcorvette.com/instructi...al_secured.pdf
The link shows the vacuum hose schematics for '68-'82. I traced the vacuum lines on the car and compared them to the schematic. Well, as it turns out, the red and yellow vacuum lines were reversed at the wiper vacuum actuator relay valve. So, I attached the red and yellow vacuum hoses according to the schematic and -BINGO - the door opens and everything operates as it should.
As I mentioned earlier, I did replaced the wiper vacuum switch. The switch did need adjusting, however, for the door to close properly.
PeteZ06..........You've got excellent taste in cars!!!
http://willcoxcorvette.com/instructi...al_secured.pdf
The link shows the vacuum hose schematics for '68-'82. I traced the vacuum lines on the car and compared them to the schematic. Well, as it turns out, the red and yellow vacuum lines were reversed at the wiper vacuum actuator relay valve. So, I attached the red and yellow vacuum hoses according to the schematic and -BINGO - the door opens and everything operates as it should.
As I mentioned earlier, I did replaced the wiper vacuum switch. The switch did need adjusting, however, for the door to close properly.
PeteZ06..........You've got excellent taste in cars!!!
