71 wiper door technical assistance needed
Thread Starter
Instructor
Joined: Oct 2005
Posts: 204
Likes: 4
From: Sunny Florida
71 wiper door technical assistance needed
Current issue - start car and wiper door raises and stays in up position with wiper system shut off. Pulling the override switch has no affect.
Previously - wiper door did not work. Replaced the seal on the wiper door actuator on the firewall and replaced the wiper vacuum actuator Relay in the fender well and system worked fine
After a month, the door now raises on startup and stays up.
I have replaced the vacuum solenoid under the wiper arm and adjusted it to correct position, but no resolution.
The vacuum to the filter from the manifold is good as well as at the splitter. Vacuum is held after the car is shut off.
Headlight doors work fine and with the override as well.
Vacuum to the small port on the wiper door actuator relay is good and matches the strength of the headlight actuator relay small port. The center white vacuum line on both the headlight and wiper door actuators is good.
Pulling the red vacuum line on the wiper door actuator relay and plugging it on to the top port closes the door.
I am guessing the wiper door actuator relay or the tach mounted solenoid is bad.
Any troubleshooting ideas to locate the issue?
Any help is appreciated.
Thanks
steve
Previously - wiper door did not work. Replaced the seal on the wiper door actuator on the firewall and replaced the wiper vacuum actuator Relay in the fender well and system worked fine
After a month, the door now raises on startup and stays up.
I have replaced the vacuum solenoid under the wiper arm and adjusted it to correct position, but no resolution.
The vacuum to the filter from the manifold is good as well as at the splitter. Vacuum is held after the car is shut off.
Headlight doors work fine and with the override as well.
Vacuum to the small port on the wiper door actuator relay is good and matches the strength of the headlight actuator relay small port. The center white vacuum line on both the headlight and wiper door actuators is good.
Pulling the red vacuum line on the wiper door actuator relay and plugging it on to the top port closes the door.
I am guessing the wiper door actuator relay or the tach mounted solenoid is bad.
Any troubleshooting ideas to locate the issue?
Any help is appreciated.
Thanks
steve
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
I'm thinking that the safety interlock [vacuum] switch that is under the right-side wiper is not adjusted to its correct position. If the wiper does not fully depress the switch plunger, your symptoms will be the result. You may have to elongate the mounting holes on that switch so you can move it closer to the wiper body.
To test this 'theory': with car engine OFF, use a screwdriver or other probe/rod to reach through the vent grille and see if you can further depress the interlock switch. If you can move it farther than 1/8", the switch needs to be repositioned closer to the wiper body. You can also hold down the switch button (using this method) and have someone else start the car. If this is the problem, the wiper door will not open on its own.
Another possibility is that you reconnected the three hoses going to that switch incorrectly.
To test this 'theory': with car engine OFF, use a screwdriver or other probe/rod to reach through the vent grille and see if you can further depress the interlock switch. If you can move it farther than 1/8", the switch needs to be repositioned closer to the wiper body. You can also hold down the switch button (using this method) and have someone else start the car. If this is the problem, the wiper door will not open on its own.
Another possibility is that you reconnected the three hoses going to that switch incorrectly.
Team Owner
Joined: Sep 2006
Posts: 31,267
Likes: 4,361
From: Westminster Maryland
Hi Steve,
I like 7T1's answer better...but...
There is a T in the large green hose as it leaves the vacuum storage tank. That means the 'open' vacuum supply for both the wiper door and headlight door actuators are connected. Any chance of a headlight leak that's showing up in the wiper door?
Regards,
Alan
I like 7T1's answer better...but...
There is a T in the large green hose as it leaves the vacuum storage tank. That means the 'open' vacuum supply for both the wiper door and headlight door actuators are connected. Any chance of a headlight leak that's showing up in the wiper door?
Regards,
Alan
Thread Starter
Instructor
Joined: Oct 2005
Posts: 204
Likes: 4
From: Sunny Florida
71 wiper door issue
I'm thinking that the safety interlock [vacuum] switch that is under the right-side wiper is not adjusted to its correct position. If the wiper does not fully depress the switch plunger, your symptoms will be the result. You may have to elongate the mounting holes on that switch so you can move it closer to the wiper body.
To test this 'theory': with car engine OFF, use a screwdriver or other probe/rod to reach through the vent grille and see if you can further depress the interlock switch. If you can move it farther than 1/8", the switch needs to be repositioned closer to the wiper body. You can also hold down the switch button (using this method) and have someone else start the car. If this is the problem, the wiper door will not open on its own.
Another possibility is that you reconnected the three hoses going to that switch incorrectly.
To test this 'theory': with car engine OFF, use a screwdriver or other probe/rod to reach through the vent grille and see if you can further depress the interlock switch. If you can move it farther than 1/8", the switch needs to be repositioned closer to the wiper body. You can also hold down the switch button (using this method) and have someone else start the car. If this is the problem, the wiper door will not open on its own.
Another possibility is that you reconnected the three hoses going to that switch incorrectly.
Hi Steve,
I like 7T1's answer better...but...
There is a T in the large green hose as it leaves the vacuum storage tank. That means the 'open' vacuum supply for both the wiper door and headlight door actuators are connected. Any chance of a headlight leak that's showing up in the wiper door?
Regards,
Alan
I like 7T1's answer better...but...
There is a T in the large green hose as it leaves the vacuum storage tank. That means the 'open' vacuum supply for both the wiper door and headlight door actuators are connected. Any chance of a headlight leak that's showing up in the wiper door?
Regards,
Alan
Thank you for the response. I had already changed the interlock switch and had concern it might have been defective. I double checked the hoses and they are routed correctly. I have more than an 1/8" in the seating of the switch so tried the long screwdriver idea to completely close the switch and had the car started. The door still pops up when the car is started. I am thinking the switch is good for the time being, but have not discounted it may be defective. If I remove the red striped hose from the switch the vacuum is released and I can push the door closed
Thanks again for your thoughts. Steve
Alan,
Thanks for the reply. I looked into the vacuum tee fitting and pulled the green hose off the tee and closed both the tee and hose leading to the headlight actuators. Started the car and again the wiper door pops up when started. There is good vacuum on the tank side of the tee. After shutting off the car and removing the cap on the tee the vacuum is released and I can again push the door closed. It seems the vacuum in the system is maintained after the car is shut off for a long time. Again thanks for the advice.
Steve
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
I take it you have made sure the hoses to the vacuum can for the wipers are on the correct sides of the can on the firewall. Maybe the vacuum hoses to the soleniod behind the tachometer are not routed or connected correctly? It is also possible to have a bad soleniod valve, this valve is electrically activated by the wiper switch to open the door. What fun we 68-72 owners have with our GM styling features
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Do you have the red hose on the port closest to the small port ?
Thread Starter
Instructor
Joined: Oct 2005
Posts: 204
Likes: 4
From: Sunny Florida
71 Wiper door issue
I take it you have made sure the hoses to the vacuum can for the wipers are on the correct sides of the can on the firewall. Maybe the vacuum hoses to the soleniod behind the tachometer are not routed or connected correctly? It is also possible to have a bad soleniod valve, this valve is electrically activated by the wiper switch to open the door. What fun we 68-72 owners have with our GM styling features
Still............a day in the garage is better than..............
Steve
...Roger...
I appreciate your insight. You pegged it! Red hose is on the correct port, but no vacuum on the port or red hose. I am thinking some dirt got into the relay.
Problem solved!
Thank you very much!
Steve
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