Yes if you connected the red to the white that should have closed the door "IF" the RED had vacuum on it and in turn the white had vacuum.

 

Assuming you started the car after you connected the two hoses together...

Yes, because it removed the leak and is now supplying vacuum to the relay which by default keeps the door shut. Removing the vacuum opens the door.

cc

BTW, I stated it wrong in post #11 above. When the wiper valve is depressed by the wiper arm vacuum is supplied to the white striped hose from the red striped hose. This causes the relay to supply vacuum at the large red striped hose which keeps the wiper door shut.

When the wiper valve is released vacuum is removed from the white striped hose which is then vented to the ether which causes the relay to switch vacuum to the large green striped hose on the actuator to open the wiper door.

 

Ok, a few more details.

This time I just bypassed the relay all together. I checked the green vacuum hose that is connected to the aft end of the door actuator. This hose has vacuum and is forcing the door open. Pushing on the door does not overcome the force of this actuator holding it open.

But connecting that to the other end of the actuator... the door does not close on its own, but with a little hand pressure I can close the door with the engine running. I'm thinking this could be because the door is physically a little stiff (I might try freeing it up with some WD-40, etc). However, switching that green hose back to the other side and the door pops right up.

So I havn't figured out the control switch yet, but it appears theres more than one problem going on here. Furthermore, upon closer inspection it looks pretty obvious the passenger side wiper arm is interferring with the door. I believe someone replaced it with the wrong wiper blade and then bent the arm to fit... Anyone have a part number for a good wiper replacement?

 

Update... still havn't solved this problem, but making progress.

Moving the door up and down by hand over time free'd up the wiper door. Changing the green vacuum hose back and forth on the actuator causes the door to open and close freely.

If I get vacuum to the relay, the door works correctly. I replaced the switch thinking I had a faulty wiper arm position switch, since vacuum was not reaching the relay. That didn't solve the problem...

I have vacuum going into the switch via the red input. However, I just discovered the problem is it is weak. If I go directly from the vacuum tap off of the engine to the red line the entire system works, the switch.. to the relay.. to the actuator to close the door. I verified the integrity of the switches input solid/rubber line by connecting the solid line input on the drivers side to the 1v2 vacuum tap-off of the intake.

So the insufficient vacuum seems to be a problem under the dash. The overrides are in their correct positions and the the **** works normally. I have a white vacuum line coming in from the engine tap-off. This line goes to the headlamp override switch. The other override switch has a red line that comes off and goes around to the relay... pressing these together closes the door and further isolates the problem to between these two connections.

 

So the insufficient vacuum seems to be caused by a faulty tach/wiper door solenoid. Vacuum in but no vacuum out, pulled the solenoid to confirm.

Is there anyway to repair the thing, I see they are pretty expensive?

 

Thread revival...

The tach solenoid was at least partially to blame. Rebuilt it vice replacing. I drilled out the rivets holding it together, cleaned it (it was filled with dust and debris), and riveted it back together. Here's a reference thread

Rebuilding faulty tach/wiper solenoid

The problem I'm having now is the door likes to pop open when I'm driving. I have noticed from time to time that the vacuum is being dumped at the wiper position switch relay. I can stop the dump by pushing down on the passenger wiper to make sure it's properly seated on the relay. But that doesn't really seem to close the door... So I'm still digging!

 

Door popping up when driving usually is the small hose circuit loosing vacuum momentarily,the 3 port check valve can cause this.
Pinching and isolating is the best way (other than replacing everything) to diagnose.

 

Roger, just keep putting your consultations on my tab. I appreciate everything.

Right now, when I fire the car up the door was popping up immediately. I removed the source vacuum line (yellow input line in the diagram below, white on my car) to the relay under the left fender and checked for vacuum. Checked good, so I reinstalled and viola, the door closed.

So I tried turning on and off the wipers. Door popped open (so the solenoid seems to be working) and wipers came to life. Turned them off and the door stayed open. Now all I have to do is push down on the wiper arm to close the check valve and the door closes.

Not sure what I did when I was testing these vacuum lines, removing and reinstalling...? It is worth mentioning that I do hear a hissing sound near the wiper door actuator. This sound is either a vacuum LEAK (that I can't find) or the sound of vacuum just moving through the actuator and hoses in that vicinity. When I remove vacuum to the entire wiper system the sound definitely goes away...

Roger, when you say 3 port check valve are you referring to the switch under the pass wiper arm, aka "control valve" as its defined previously in this thread (shown in the upper left corner of this diagram)? It is definitely dumping vacuum anytime the wipers are turned on, then off. Each time the wiper arm does not fully seat and I have to press down on the arm to get the control valve to close the dump.

 

The 3 port check valve as I call it is the silver metal check valve at the intake maniold just past the white filter.

On the sound of a leak at the actuator- not sure if the door is up or down but try pinching the green or red hoses and see if one of those stops it-if they dont then the leak is elsewhere and the sound is just transmitting to that area. Then try pinching the yellow going into the relay under the fender-if this stops the sound the relay is most likely leaking.
The control valve under the wiper arm could be the source of the vac leak noise. That valve can be a pain to get adjusted correctly and get the wiper arm to push it down ever time. The wiper arms have to be adjusted correctly and the mechanism cant have slop in it or it wont push the valve far enough.

 

This is a great thread.

Dont want to hijack it but I have a question

My wiper door and lights work fine but the wiper door opens when i start and sometimes when I accelerate hard then back off.

I think I now understand how it all works and have been doing testing as has been mentioned.

With a vacuum pump attached to the tube that goes through firewall I tested the following so far:

. open both overrides under dash and it holds pressure (for 5-10 minutes)
. close wiper override and it wont hold pressure.
. block tube before wiper return switch and it holds pressure.

So the wiper return switch seems to be playing up.

After a bit of playing it seems the switch works as follows....I assume this is not correct.

When its not depressed the vacuum is routed to the open pipe.
When its depressed 3/4 it send vacuum to the relay.
When its depressed more than 3/4 it routes vacuum to the open pipe.

So by lifting the wiper slightly (so the switch come up a bit) I could hold vacuum all the way to the relay in the passenger fender.

Do i need a new switch of can they be cleaned etc?

 

So if I understand correctly, you're talking about the wiper control valve, or "switch" under the passenger side wiper arm pivot?

If that's the case, your point is just that the wiper arm has to depress the valve only 3/4 of the way for it operate correctly, IE pass the vacuum along to the relay? If you can get it to work buy pulling up on the wiper, maybe you solution is the same one Roger suggested to me. There should be some adjustment allowable in the "switch," aka wiper control valve. Adjusting it so it doesn't depress fully with the wipers stowed might solve your problem.

Let me know if I missed the boat with this one...

 

I tried that and got very close to it working however it always lost a bit of vacuum.

So i pulled the wiper control valve and put it underwater with some pressure on it.....hmm leaks a bit at top and bottom all the time.

Easy then i will order a new one.

This thread and the comments by Roger and some others has helped me understand how it all works - Not as complex as it first seemed. - Thanks guys

 

This wiper door has got to be the funniest damn thing I've had yet on these cars. I am determined for it to work 100%! It just taunts me now, has taken on a life of its own. Ha.

The door definitely closes and opens at random times. I believe it is related to when the motor is generating more vacuum (?) ie it seems to close after the car has been running a while. I was driving earlier today and noticed it would go down, and then creep halfway up, back down. Kinda funny. The most consistent time for the door to pop up is on start up.

I suspect the relay under the fender is the leaking culprit. Based on Rogers advice I tried isolating the leak. When I disconnect its input (yellow line on our diagram) the sound goes away. Interestingly my hose is black with a white line, not yellow. And all three of the hoses are the same diameter, I suspect one of them is too large, the result is that one can not sit comfortably on its nozzle because it is interfered with.