Welcome to the Corvette Forums at the Corvette Action Center!



Randy 71

VETTERS, Question. Wiper door is slow to open when I use the pull switch under the steering wheel. Additionally, when I start the car it will open by itself and then close. I know it probably a cracked or lose vacum line. The question is based on what I have said, does anyone know where I should start looking first? PS. The head lights work fine. Thanks.
wiper door

Go to the NCRS website and click on "discussion boards" then select "technical Board" or "technical archives". In the technical board you can post your question or better yet search the archive for "vacuum, wiper door" You'll be amazed at the amout of super accurate info there from people who live eat and breath vettes. The address is, http://www.ncrs.org. Join!! It's the best $30 dollars you ever invested in your vette. I read a thread there about a month ago that addressed your problem exactly. Good Luck, and stop driving that classic in the rain.
I feel your pain man

Windshield wiper doors and headlight vacuum problems are a PIA. While Ken has a good idea, I have yet to figure out how to search on the NCRS board........I may figure it out someday:). But, I will try to give you a couple of things to check. First, check the vacuum valve near the intake, it is an aluminum looking thing with three hoses connected to it, one hose is comming from the intake, one is going to the vacuum tank, and the other is going through the firewall. This valve is a one way only valve, it works a little like a diode, if we were talking about electricity. You should be able to blow through it in only one direction. Ok, let me try to explain why it works this way. The vacuum operated switches are operated bass akwards then you would think. The small hose on the relay is the "control", it has constant vacuum until the wiper door, or what ever is turned on. When vacuum is removed it allows the vacuum to flow through the switch therefore operating the device. A good example of this is, with the car running and the lights off, pull, or pinch off the small hose, blocking the vacuum. What happens?? The headlight comes up. Now, after all that, what is the valve for and what does it do. When you first start the car there is no vacuum is the tank. After the car runs for just a little bit the tank fills with vacuum, as long as there is vacuum, the headlights and wiper door will stay down. As you accelerate, vacuum drops, if the valve is bad, it allows the vauum to drop from the tank also therefore takeing vacuum away from the "control" hose, therefore allowing the wiper door or headlights to raise. Why, the wiper door first? Well, somtimes it is the headlights. It just depends on which has the least resistance, or which the vacuum is removed from first.........I hope this helps. I know that wiper door and headlights can be difficult to get to work correctly. This may not be the problem, but this is where I would look first........Steve

Do you happen to sell cans of vacuum in your shop?
Tom, 6 pack for $2.00. Also I think I still have a can of Florida sunhine somwhere. But I think I may open it tommorow......:)Steve

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors


MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Advertise with the Corvette Action Center!

Double Your Chances!

Our Partners

Top Bottom