72 wiper door solonoid test

[Robert B.]

Can anyone help with a test to see if the vacuum part of the wiper solonoid works correctly? The solonoid I am describing is located attached to the tachometer under the drivers side dash. It has three ports (one is a vent) there is also an electric connection. Is there anyway to check this with a vacuum pump? The electric part seems to work.

Also if the round windshield wiper switch (located between the two vac overide switches) is in the on position should it block the windshield wiper switch from operating?

Thanks

[Alan S.]

Re: 72 wiper door solenoid test

Hi Robert,
I have a test procedure for the vacuum control solenoid, but at work. If no one replies I'll send it to you Monday.
My understanding is that the rotary knob does override the wiper switch. The wiper switch is in the on position so the wipers come up, the rotary knob stops the wipers but the switch remains in the on position so its being overridden. When you turn the rotary knob again the wipers continue on their merry way until you turn the switch off. If you turn the switch off while the rotary knob has the wipers stopped, when you turn the knob again to release the wipers, they just complete their cycle and go to the park position.
Regards,
Alan

[Jack H.]

Re: 72 wiper door solenoid test

Correct, the round knob kills power to the WSW motor causing it to stop sweeping. Purpose: allow mechanics access to change wiper blades.

On the solenoid, all cockpit vac controls work alike: they vent vac to actuate the items they control. So, when the solenoid energizes the vent path opens and when the solenoid is de-energized the vent closes.