I'm a first time vette owner. 72 with a wiper door that will stay down when pushed down with car off but when I start the car the door comes back up. I tried turning the override switches to no avail. can any one tell me what to check next?
Thanks

 

Hey Tim, welcome to the forum. The wiper override switch you turned under the dash stops the blades on the glass so you can change the blades. There are two pull down switches, one on either side of the ****, that should be in the up position. One pull down is for the headlights and the other is for the wiper door. Make sure both are in the up position.

 

Sounds like you go a bad wiper door solenoid. This is located behind the Tach and it is not easy to get to. What happens is this gets dirt in it allowing the vacuum to get past the seal and open the door. You can find them used but it can be taken apart and cleaned. Drill the rivets out and take it apart making sure you note how it comes apart for reassembly. After you clean it get some 1/8 rivets and put it back together. Good luck. I love my wiper door system. I get all the oohhss and aahhss when I use my wipers.

 

Could be your wiper is not hitting the Vacuum switch under the grille in front of the door. Try pushing down RHwiper arm with a thin piece of wood and see if the door returns to the park position.

 

My vote is for the solenoid behind the tach. Had the same problem and that's what fixed it. By the way, if you decide to find a replacement solenoid, you can find them at ZIP Corvette Parts. (Ask me how I know.) Good luck.

 

Actually that switch keeps vacuum from the door while the wipers are sweeping so the door will not close until the wipers are parked. This prevents the door from closing on the wiper arms. If the door is opening on startup then 9 out of 10 times it's the solenoid.

 

In his post he says the door is opening on startup after he pushes the door down by hand with the motor off. So, the wiper park vaccum switch under the passenger wiper arm would be a valid place to start. The door would stay open (and want to pop open upon startup of the motor) if this switch is not depressed or is not functioning properly. Another thing that would cause the wiper door to pop-up on startup (after being forced down by hand w/motor off) would be if the manual over-ride vaccum switch were pulled down.

Tim, are you only having issues with the wiper door or are you having pop-up issues with your headlights as well?

 

hammer head you are right on the money, when I push the door down with the car off it stays. When I start the car it pops up. No problems with the lights. Sure do appreciate the help guys!

 

Ok, it stays down when the car is off because there is no vaccum to keep it open. By the way "door open" is the default position should you have a system failure (headlights too) that way you have wipers and lights should the system fail.

Now;
Assuming for the moment that the previous owners of your car haven't bubba'd up any of your wiring or vaccum hoses you should check the following three things first.
1) That the wiper switch at the center of the dash is off AND that the wiper over-ride switch is also off (think of it as a bolt - left is off). WHY, because the dash switch will be telling the door to open but the over-ride switch will be preventing the wiper motor from running which will make you think that the dash switch is off (but it's not). Sounds obvious but happens to the best of us. If true then simply slide the dash switch to the off position and turn the over-ride switch to the right and you're good to go.
2) That the underdash wiper door vaccum valve is closed. As explained above by Eddie70 this valve (it's a pull/push valve next to the over-ride switch) causes the wiper door to stay open for maint and/or intermittent wiper operation (don't wanna be opening and closing the wiper door when it's just misting outside). To put the door down the valve should be pushed up toward the steering column. The valve is located right beneath the steering column next to the over-ride switch and the headlight vaccum door valve.
3) If neither of the above resolve your issue then it's time to check the wiper arm vaccum valve located in this diagram. This valve has a plunger that the passenger arm pushes down when it reaches its park position. The prevents the wiper door from closing on the wiper arms before they are parked. With this motor running (remember all this stuff works of engine vaccum) simply push down on the plunger to see if the door will close (you could also push the wiper arm against the plunger).

OK, if none of the obvious things correct your problem then report back.

 

Thanks: sounds like good stuff and I will check on friday after work or satuday and report back
sure do appreciate the help I thought I would need to learn all the tricks myself but you guys sure do save alot of time for me,
Thanks again

 

still doesn't work after I checked all.
I I blow thru the vacume hose I hear air near the fender. It seems to be coming out of a vacume relay is this normal ?

 

try switching these vaccum hose, they may be backwards, so when the plunger is pushing, it may be causing the door to open. i believe they have 3 tubes, but only 2 get hoses (top 2)

If neither of the above resolve your issue then it's time to check the wiper arm vaccum valve located in this diagram. This valve has a plunger that the passenger arm pushes down when it reaches its park position. The prevents the wiper door from closing on the wiper arms before they are parked. With this motor running (remember all this stuff works of engine vaccum) simply push down on the plunger to see if the door will close (you could also push the wiper arm against the plunger).