Wiper door goes up and back down when I start the car. It stays up after I shut the motor off. Most of the parts, hoses, relay, etc..., have been replaced. The vacuum tank is also new. The lights work fine. Any ideas to look for?

 

You have a leak ,most likely in the small hose circuit.
One common part to fail or be out of adjustment is the safety switch or valve under the passenger wiper arm.

 

Hi,
I agree that the wiper door dancing at start up is a small hose, (relay control), issue.
The hose size determines which circuit , (control, [small], or servo ,[large] ), receives full vacuum first. A leak in a small hose or vacuum relay allows the large hose and relay to receive full vacuum and operate the wiper door actuator so moves first.
Then the control side receives it's vacuum and the relay is able to signal the actuator to close because that's where the wiper switch is presently set.
But, to the last point, isn't having the door stay up at engine shut off normal... everything stays where it is at the moment you shut off power?
Regards,
Alan

 

If the wiper door is open and the wipers are working when you shut off the engine, then, Yes, it should stay open. But, if the wiper door is closed and the engine is shut off, some cars will have the wiper door open and then close all or part way, after several seconds have passed.

I believe that this is a 'vacuum timing' issue, and is caused by some vacuum leakage resulting in the residual vacuum in the system being stronger on one side of the actuator can..or on the other side..after the car has been turned off. Possible causes may be: blockage in the metal [vacuum] transfer tube that runs from one side of the engine bay to the other along the firewall; leakage in the internal seal inside the 'wiper DOWN' safety switch; leakage [or poor seal] in the vacuum solenoid/switch [behind tach housing]; defective check valve; hose or connection leaks in the system.

By design, the 'close' side of the wiper door actuator should always have more vacuum on it than the 'open' side does. But, with wear/tear in the system, the opposite can happen and the result is the "phantom" wiper door syndrome. So, leakage points on the 'open' side of that system should be minimized to keep that from happening.

P.S. Other than being a nuisance, that 'problem' really causes no harm and the wiper door still should operate correctly when the engine is ON and the wiper switch is moved.

 

Mine did that when I bought the car (and for several years after) except it would only open a small amount when I shut the car off.

The wiper blades were some sort of replacement ones and they were really large (thick)
Seemed like where the car was off and sat for a bit they pushed the door just off the home position and when I started the car it cycled once and squashed the wipers down.

I played with the wiper timing issue because I though they weren't going down far enough to the home position and the door was touching them when it closed.

I changed to the new style one piece (no steel frame) wiper blades which are considerably thinner and the problem went away

Take a piece of cardboard (cereal box etc) and with the door closed, slide it along and see if it is touching the wiper arms/blades. If it is, maybe pop the arms or blades off and see if the problem goes away

Mooser

 

Check the white plastic filter in the vacuum supply line from the manifold and the metal two port valve further along.

 

Thanks for the replies. I'll look into some of the suggestions and post how it goes. This is a maddening little glitch!!