Early C3 windshield wiper sys. info
Thread Starter
Pro Mechanic
Joined: Oct 1999
Posts: 3,922
Likes: 1,468
From: South-Central Coast California
Early C3 windshield wiper sys. info
There is a seeming bit of confusion on early C3s with the hidden wipers.
To lock the wiper door open, I thought you, pulled down the right vacuum valve under the column then shut the engine off and the door stays open, however, some service manuals suggest manually moving the diaphragm in the wiper door actuator to manually open the door and lock it open.
So here's the question...
Do ALL '68, '69, '70, '71 and '72 Vettes have the two vacuum valves and the manual wiper motor switch under the steering column?
To lock the wiper door open, I thought you, pulled down the right vacuum valve under the column then shut the engine off and the door stays open, however, some service manuals suggest manually moving the diaphragm in the wiper door actuator to manually open the door and lock it open.
So here's the question...
Do ALL '68, '69, '70, '71 and '72 Vettes have the two vacuum valves and the manual wiper motor switch under the steering column?
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,137
Likes: 4,248
From: US-PNW
I believe they all have the over-ride valves, for headlights and wiper door, and the wiper motor switch - at least I think '68 had them and know that my '72 has all three. I've never read about manually moving the door actuator to make this happen. Perhaps if you can't start the engine or something it would be a method to open the door, much like the way you can push up on the headlight knee joint to open those doors.
Race Director
Joined: May 2006
Posts: 18,737
Likes: 2,583
There is a seeming bit of confusion on early C3s with the hidden wipers.
To lock the wiper door open, I thought you, pulled down the right vacuum valve under the column then shut the engine off and the door stays open, however, some service manuals suggest manually moving the diaphragm in the wiper door actuator to manually open the door and lock it open.
So here's the question...
Do ALL '68, '69, '70, '71 and '72 Vettes have the two vacuum valves and the manual wiper motor switch under the steering column?
To lock the wiper door open, I thought you, pulled down the right vacuum valve under the column then shut the engine off and the door stays open, however, some service manuals suggest manually moving the diaphragm in the wiper door actuator to manually open the door and lock it open.
So here's the question...
Do ALL '68, '69, '70, '71 and '72 Vettes have the two vacuum valves and the manual wiper motor switch under the steering column?
Racer
Joined: Apr 2020
Posts: 264
Likes: 200
From: Sicklerville NJ
2022 C3 of the Year Finalist - Unmodified
Don`t all of these actuators have a rubber plug at the engine side in them?? On my early 69 you can remove this plug and with a screw driver push in the diaphragm to open up the door.
Steven
Steven
Safety Car
Joined: May 2001
Posts: 4,759
Likes: 1,647
From: Fairfax Virginia
Yes, on my early 1968 C3 (#2595) there are two vacuum override switches and one windshield wiper power control **** under the right side of the drivers area of the dashboard.
On the early 1968 C3's there are the two vacuum override switches and the one ****. The **** simply allows you to stop the wipers in mid-motion. Of the two Vacuum override switches, one of the vacuum override switches controls the headlights, allowing them to go up and stay up regardless of the headlight switch position. The second vacuum override opens the "enclosed" wipers and keeps the cover open while the over-ride is pulled back. If I shut off the engine while the vacuum override is activated it stays activated and does not go back down. This is the way my car was set up before I bought it.
On the early 1968 C3's there are the two vacuum override switches and the one ****. The **** simply allows you to stop the wipers in mid-motion. Of the two Vacuum override switches, one of the vacuum override switches controls the headlights, allowing them to go up and stay up regardless of the headlight switch position. The second vacuum override opens the "enclosed" wipers and keeps the cover open while the over-ride is pulled back. If I shut off the engine while the vacuum override is activated it stays activated and does not go back down. This is the way my car was set up before I bought it.
Thread Starter
Pro Mechanic
Joined: Oct 1999
Posts: 3,922
Likes: 1,468
From: South-Central Coast California
Thanks for the information, people.
My '71 has both valves and the rotary switch. I've confirmed that '68 and '72 have them so all the early C3s must have them.
It's interesting that Service Manuals from that era tell techs to pop the plug out of the actuator and push the linkage to open the door manually. I wonder why the books say that when one can just manually open the door with the right-hand override valve.
I guess the answer is lost to history because after 54 to 57 years, the engineers who knew are dead.
Again, thanks for your answers.
My '71 has both valves and the rotary switch. I've confirmed that '68 and '72 have them so all the early C3s must have them.
It's interesting that Service Manuals from that era tell techs to pop the plug out of the actuator and push the linkage to open the door manually. I wonder why the books say that when one can just manually open the door with the right-hand override valve.
I guess the answer is lost to history because after 54 to 57 years, the engineers who knew are dead.
Again, thanks for your answers.
Melting Slicks
Joined: Sep 2006
Posts: 2,815
Likes: 470
From: Wichita Kansas
Thanks for the information, people.
My '71 has both valves and the rotary switch. I've confirmed that '68 and '72 have them so all the early C3s must have them.
It's interesting that Service Manuals from that era tell techs to pop the plug out of the actuator and push the linkage to open the door manually. I wonder why the books say that when one can just manually open the door with the right-hand override valve.
I guess the answer is lost to history because after 54 to 57 years, the engineers who knew are dead.
Again, thanks for your answers.
My '71 has both valves and the rotary switch. I've confirmed that '68 and '72 have them so all the early C3s must have them.
It's interesting that Service Manuals from that era tell techs to pop the plug out of the actuator and push the linkage to open the door manually. I wonder why the books say that when one can just manually open the door with the right-hand override valve.
I guess the answer is lost to history because after 54 to 57 years, the engineers who knew are dead.
Again, thanks for your answers.
