1968 Wiper Door Help????
Thread Starter
Le Mans Master
Joined: Mar 2000
Posts: 9,127
Likes: 2,326
From: Pottsville, PA. USA Home Of America's Oldest Brewery Yuengling
1968 Wiper Door Help????
I am working on a 68 wiper door. Here is my question. I have a new door actuator and a new relay valve. I have all of the hoses hooked up and have both parts laying on the fender. When I pull the bypass switch down the rod doesn't move on the actuator.
I have vacuum in the red hose coming out of the valve to the actuator, I also have vacuum at the bypass switch and the solenoid switch but the rod won't pull out when the by-pass switch is pulled down.
If I unhook all of the vacuum hoses on the actuator and take the red hose and hook it up to the rear port the rod comes right out, and if I hook it to the front port the rod goes in. So I know the actuator is working.
I even switched the by-pass switch with the headlight one and it still will not pull the rod out.
Any Ideas what is wrong or where to look next?
I have vacuum in the red hose coming out of the valve to the actuator, I also have vacuum at the bypass switch and the solenoid switch but the rod won't pull out when the by-pass switch is pulled down.
If I unhook all of the vacuum hoses on the actuator and take the red hose and hook it up to the rear port the rod comes right out, and if I hook it to the front port the rod goes in. So I know the actuator is working.
I even switched the by-pass switch with the headlight one and it still will not pull the rod out.
Any Ideas what is wrong or where to look next?
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
The system is rather simple actually. Vacuum is supplied to the switching valve through the center(large) port and a signal vacuum is supplied to the valve through the small line. All of the controls on the inside, only turn on or off the vacuum (small line) to the valve. So you need to make sure that the inside controls are sending that signal to the valve. Either off or on. Off will cause the door to open.
Thread Starter
Le Mans Master
Joined: Mar 2000
Posts: 9,127
Likes: 2,326
From: Pottsville, PA. USA Home Of America's Oldest Brewery Yuengling
It has vacuum at the center port and it also has vacuum on the small white hose. It just won't make the shaft move out.
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
My guess is the under-dash bypass switch; either somewhere along the hoses leading to it or the bypass switch itself.
How is your headlight vacuum? If it is lazy, you WILL see it in your wiper door behavior. I replaced the entire hose system with a kit from Dr Rebuild as it is all connected (headlight and wiper door actuator vacuum). Found my problem on my '69 to ultimately be a combination of rotted vacuum hoses (originals) and the relay valve under the wiper door. Then, the hole where the wiper door screw attaches to the arm decided to strip out and now, I have to manually open the door until I resolve the bad threads.
How is your headlight vacuum? If it is lazy, you WILL see it in your wiper door behavior. I replaced the entire hose system with a kit from Dr Rebuild as it is all connected (headlight and wiper door actuator vacuum). Found my problem on my '69 to ultimately be a combination of rotted vacuum hoses (originals) and the relay valve under the wiper door. Then, the hole where the wiper door screw attaches to the arm decided to strip out and now, I have to manually open the door until I resolve the bad threads.
Racer
Joined: Jul 2006
Posts: 499
Likes: 0
From: Colebrook Connecticut
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Le Mans Master
Joined: Mar 2000
Posts: 9,127
Likes: 2,326
From: Pottsville, PA. USA Home Of America's Oldest Brewery Yuengling
I found the problem. At sometime someone broke off the nipple on the control valve for the green hose. They put a new valve on the car and the nipple was stuck about one inch into the hose. This had the vacuum blocked and the door wouldn't open or close. I removed the nipple from the hose and it works fine.
Thanks for all of your help.
Thanks for all of your help.