My wiper door, and my headlight doors used to work flawlessly. Headlights still work well, but the wiper door will not go up when I hit the switch. If I pull the override lever I can pull the door up with my hands...then when I push the override in the door sucks down. When the door is open the dash switch will turn on the wiper blades when pushed to the right.

Any hints?

Thanks,
Dennis

 

Vacuum issue.

 

The control line seems to be working, since pulling override seems to be cutting the vacuum to the relay, and allowing you to pull the door up. And pushing it in is supplying vacuum to the relay, and the relay is supplying vacuum to the down side of the actuator. I would say the problem is either the relay is not providing vacuum to the 'up' line when the control vacuum is cut of, or the problem is with the actuator not working on the up side.

Check the lines going to the actuator. When the override is pushed in, you should have vacuum on the down/engine bay side of the actuator. When you pull the override out, you should have vacuum on the up/wiper bay side.

If you have vacuum on the up side of the actuator when the override is pulled out, then I would say the problem is with the actuator. If you do not have vacuum on the up side, then I would say you probably have a problem with the relay.

The actuators, either wiper, or headlight, the side with the rod will be the 'up' side (should be a green line), and the other side is the 'down' side (should be a red line). On the relay, the line in between the red, and green, should be a yellow line, that is the source, and should have vacuum all the time. The smaller hose should have a white line, and is the control. When it has vacuum, the relay should direct the source vacuum to the red/down line. When the vacuum is blocked on the control line (by an override, or the headlight switch, or the wiper solenoid) then the relay should direct the source vacuum to the green/up line.

My guess is that the green/up line has pulled away from the back side of the actuator, or has come loose at the relay.

 

Check the wiper door solenoid on the rear of the tach.

 

check the small bellows seal on the actuator shaft. Mine will sometimes pull out of the can and the door will not open.

 

It always seems to be this inaccessible little twit.

I also had a bad wiper door vacuum relay. It's mounted on the back side of the right wheelwell on a 72.

 

Thanks, I will check out all of the above. Sounds like it is something that is simple.

Dennis

 

If you use the pull down and the door fails to come up.. go to the relay on the fire wall and pinch off the black hose with the white stripe. This should make the door open. If it doesn't or you can't pinch it tight enough pull the hose and block it. No vacuum to the top of the relay should make the door open.

You may have a bad relay..

Here is a video on how to test the relay.

http://willcoxcorvette.com/product_i...ducts_id=27606

 

I found that the hose going into the bottom side of the door actuator had oblonged itself and would not get enough vacuum. Vacuum probllems fixed but the wipers still dont work. Good luck