My 71 has a vacuum switch mounted with tach on the back of it.I see in assy manual.They don't say what its for just that its a switch.It's seen better days and trying to find out what it dose to order a new one.I removed the dash to spiff it up and found the contacts on it very loose.

 

It makes the wiper door open. The wiper switch activates it. Lou.

 

Yes. That is the primary switch for making the wiper door open and close. The switch under the right-side wiper is the 'safety interlock' switch that assures the wipers are in parked position before the door is allowed to close.

 

Hi,
Beating a dead horse!
The headlight switch is both an electrical switch and vacuum relay.
The wiper switch is only electrical, but it also signals the wiper door solenoid valve to supply the vacuum to open the door.
Regards,
Alan

 

Do you need a new solenoid? Was it working before you spiffed up the dash?

 

It works.I took it apart to re dye everything.One of the contacts is very loose inside the switch.Could have been like for years.Just thought I would replace it before its starts acting up.Like to stay on top of things before they fail.

 

That solenoid is very simple, you can tell if it's working by simply checking for continuity from one terminal to the other. The two terminals are connected to opposite ends of a coil. The way the solenoid works is when 12v is run thru the coil, it creates an electromagnet that pulls in a metal needle. When not energized, a spring pushes the needle out. Vacuum can pass thru the solenoid when the needle is out (coil de-energized), and is blocked when it is in (coil is energized).


The vacuum systems for the headlights and wiper door are VERY simple. The easiest way to understand them is to look at the actuators and work back. The actuators have a vacuum line on either side, one for up, the other for down. The 'up' side will be the side with the rod, and have a green vacuum line, the 'down' side will have a red line.

The green, and red lines will run to a relay. The relay will have a yellow vacuum source line, and a smaller white control line. When there is vacuum on the small white control line, then a spring in the relay is compressed, and the vacuum source is directed to the red (down) line. When there is no vacuum on the white control line, then the spring in the relay is expanded, and the vacuum source is directed to the green (up) line.

For the wipers there is the added safety valve. Because you don't want the wiper door to close before the wipers have parked, the safety valve vents the white control line until wipers press down on the plunger. So when you turn off the wipers, the solenoid is de-energized, allowing vacuum on the white control line. That would close the doors, but the control valve will vent that vacuum, venting the white control line, until the wipers are parked and the plunger is compressed.

 

Thanks,its called a door control switch.Ordered a new one.Pricey little thing but easier to replace with dash out.

 

That rotary switch stops the motor during a sweep so you can change the wipers.

The 2 pull toggles are vacuum overrides. One for the headlight doors and the other for your wiper door. If you pull it and you have vacuum. It will bleed vacuum to the actuator relay between the horns for the lights or the passenger fender for the wiper door. It opens the small diameter vacuum line on the top of the relay releasing the vacuum. That allows the internal soring to push the hour glass shaped plunger from top of the vacuum valve to the bottom. The vacuum source is the middle hose. Its black with a yellow stripe. The valve will drop from the upper hose which has a red stripe which is the engine side pulling the can innards towards the front closing the door. It drops towards the green stripe hose slowly so it can draw a vacuum on one hose while slowly purging the other. The green hose pulls vacuum and it forces the can to make the door open.




Actuator relay. The small hose with the white stripe goes to the golden nipple at the top

 

We all answered at the same time....if you dont need a rotary switch for judging I suggest getting steel toggle. It will save you some aggravation in a year or 2 when your wipers dont work and you start to take everything apart and notice that switch rotated an 1/8th of an inch.....I know

 

You know better 2013...
M

 

Dammit. I'm answering threads on my phone, no home internet and the stupid related thread crap got me.....I was on another thread about the 68 over ride and I thought this was an update as I scrolled down....we need to have that crap removed.....I AM P.O ed

 

Yeah there's a setting on the desktop to not show them but I don't know about mobile
M

 

I forgot about that setting. Thanks. I need to find the " stay logged in" button too. I have to log in on every nee thread I go to.....

 

If you do that, how will the rest of us get our "chuckles"?

[We've all answered "old" threads...........]

 

But I dont need any help looking like a clown. Wearing this make up. honking nose and giant shoes should be enough!!!! Lol