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Hello All, once again I need your help. Bought this wonderful 72 a couple months ago. But recently I have developed a problem. As soon as I start the car the wiper door opens. It stays open. After the car is turned off the only way to close the wiper door it to manually push it down. Then it stays down. Any suggestions? I guess the good news is the wipers work. Thanks in advance. Joe
First thing to check is that the over-ride switch under the steering column isn't pulled down
Then check the check-valve on the vacuum line coming off the intake, little silver thing with 1 line in, 2 lines out
Then check the park position valve that the passenger wiper arm should rest against when in the part position telling the system it's ok to shut (and keep the door shut)
After that it gets a little more complicated and harder to check but start here
M
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
get a vacuum gauge so you are not guessing. Start at the wiper parked switch. ITs "G" in the diagram. Those fail alot and the wiper actuator relay "F" does too. You would have to manually pull that override lever and its no something that isnt obvious when you do. Go back through and use the advanced search funtion on wiper door issues. There has to be a couple dozens threads about this issue and how to test and fix it......again a how to section would be very helpful in this forum.
Thanks all for your help. I'll start working on this soon. Would anyone know the part numbers for items G and F in the diagram below? Or the part numbers from vendors such as Wilcox, Zip, or anyone else? I'm having a hard time finding these two items. Many thank again.
first thing to check is that the over-ride switch under the steering column isn't pulled down :d
then check the check-valve on the vacuum line coming off the intake, little silver thing with 1 line in, 2 lines out
then check the park position valve that the passenger wiper arm should rest against when in the part position telling the system it's ok to shut (and keep the door shut)
after that it gets a little more complicated and harder to check but start here
m
Hello, I checked the overide switch and it was not pulled down. The other two items I will check in the next few days and let you know how it goes. I have a feeling this is not going to be easy but we'll get it eventually. Thanks again.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
If you have a friend with a vacuum pump it helps immensley. Attach it to the vacuum hose at the T just off the manifold and run a hose long enough to put the pump in another room if you can. Fire it up to get 15 inHg on the system and shut it off. Listen for leaks. Its the easiest way to find issues and you can put the car in the run position on the key without starting it and cycle all your vacuum accesories to see what is working. I ususally have the wiper door actuator relay fail but last summer the actual actuator bound up on mine and the door wouldnt move. Your issue is most likely one if the 2 items we all have mentioned. Good luck
Hi All. Still working on this problem. Still having the same issue. When I start the car the wiper door pops up. After turning off the car I can push the door back down. The over-ride switch under the dash is pushed up. I checked the actuator and it tested fine. I also swapped in a new actuator and it did not correct the problem. I replaced the pressure switch under the passenger side wiper and that did not help either. I have ordered a new check valve and filter from the manifold but not sure that will make a difference. The headlights work perfect. I now have a new relay. Can anyone tell me where this is located on the car, how to get to it and how to install? The AIM is not really clear on this. As always, thanks everyone for helping with this. If anyone wants to come to Greensboro NC and fix this pain in the rear issue I will pay big bucks!!!!
I wish I lived in Greensboro I would have emptied your bank account by now
have you tried spraying wd40 in the actuater it’s most likely getting stuck in the middle also cold weather plays a factor
Thanks for the response. If anyone has any constructive advice I would greatly appreciate it. This wiper door problem is wearing me out. Just trying to learn. Thanks
I swapped out the actuator with a new one and the problem still exists.
Still the problem: When I start the car the wiper door pops up. After turning off the car I can push the door back down. The over-ride switch under the dash is pushed up. I checked the actuator and it tested fine. I also swapped in a new actuator and it did not correct the problem. I replaced the pressure switch under the passenger side wiper and that did not help either. I have ordered a new check valve and filter from the manifold but not sure that will make a difference. The headlights work perfect. I now have a new relay. Can anyone tell me where this is located on the car, how to get to it and how to install? The AIM is not really clear on this. As always, thanks everyone for helping with this.
Agreed. There is an electrical/vacuum switch mounted to the back of the tachometer housing. It connects to the wiper switch and vacuum lines. Unfortunately, you'll need to, at the least, remove the top dash panel to access it. you've replaced and tested everything else.
72 wiper door problem -Ugh
