I just replaced my wiper door vacuum switch on passenger side. When I start car wiper door remains open. If I plug vent line wiper door will open a little on startup then close. Wiper system works with vent line plugged. Any thoughts?

Thanks

CK

 

Hi CK,
You replaced the interlock switch because the door was or wasn't....? What made you think the interlock was the problem.
Test the new switch:
Push plunger in, unmarked port should hold vacuum. Red and White ports should be open.
Plunger out, White marked port should hold vacuum, Red and unmarked ports should be open.
Plunger in or out, Red port always open.
A place to start.
Regards,
Alan

 

Hi Alan,

I replaced the old vacuum switch because the top was broken and the spring was out. How do I go about testing the vacuum, is there a special instrument or tool I need?

 

The wiper door actuator is controlled by the relay



When there is vacuum on the top nipple of the relay.. (the black with white stripe hose) the door will remain shut... This takes the vacuum being sucked by the yellow hose and puts it on the top large (red hose) nipple of the relay. This is the closed Nipple.

For the relay to allow the actuator to open the door, the vacuum is blocked on that small black with a white stripe hose which will cause the relay to release the plunger inside and direct the vacuum being sucked by the yellow hose to the lowest nipple on the relay (green stripe hose) either by.. 1) the wiper switch, 2) the over-ride switch. 3) the solenoid behind the tach...

So.. start with that.. and know that for the door to remain open there can not be vacuum on the black with a white stripe hose.

For the door to stay shut.. you must have vacuum on this same hose.

Now since you said the door stays open.. you need to back track that hose.. So.. make sure the over-ride plunger is not pulled.. and to to the over-ride with the car running, wiper switch off... and pull the lowest hose (closest to the ****) off of it and see if you have vacuum. You should have vacuum there and if you don't then go to the solenoid and see if you have it at the solenoid.

The solenoid.. when you turn on the wiper door switch, the switch sends ground to the solenoid on the blue wire. When this happens the vacuum is blocked by the solenoid from passing on through the system.. and as stated above when you drop vacuum, the relay switches to the green hose nipple and makes the actuator open....

Hope this helps..


Boy.. I'm working on a video of all this right now! The headlamp one is uploading to the tube as we speak... then the wiper one will be next.

 

Willcox

Thanks for the info. But why does plugging the vent hose on new vacuum switch close wiper door. Also, how do I test new switch as Alan mentions.

 

Hi C-K,
Willcox has offered some very good info.
When working on the wipers and headlights it's good to have a tool like a vacuum pump with a vacuum gauge. The gauge will show how much vacuum is in the line and will also show whether the hose or the part you're testing has a slow leak or not.
One brand is Mityvac.
Good Luck!
Regards,
Alan

 

Thanks to those who gave some great advice. I worked on the new control switch, reset the little boot over spring and everything seems to be working properly now. In the future I will check my lines to determine if I have any slow leaks. Thanks again.
CK

 

Not sure.. are you sure you have the hose's on the correct nipples? A possible answer might be that blocking the vent is allowing it to suck vacuum past the plunger seal allowing vacuum to the lower hose....

The arm switch should block vacuum while the arms are in motion... No vacuum to the relay keeps the door open...

The arm switch should pass vacuum while the arms are parked. Vacuum to the relay makes the door close...


Willcox