68 wiper motor question AGAIN!

[Joseph C.]

I have posted on this before and read all the archives. Still need some help but very close!
1 Wipers work with ignition on and wiper door open manually
2. Car running wiper door opens only when pull over ride, the wipers do not come on when turning on wipers.
3. When I turn wiper knob to stop wiper (under dash) it stops them.

So I understand it like this, I have vacuum, I have power to the wipers and I can cut the wipers off with underdash knob, but I dont have wipers when I directly turn on????
Could this be the cylinoid behind the tach and if so what wires are needed to go to that?????

[Jim T.]

Re: 68 wiper motor question AGAIN!

Joseph there is a vacuum valve underneath the wiper and grille vent on the passenger side? Have you seen it? Do you know if it has ever been replaced on your 1968?
I am not saying this is your problem, but this valve will not let the wiper door operate when using the wiper switch above the center instrument panel unless the wipers are at rest under the wiper cover. It is a type valve that should have a rubber accordian type boot on the end closest to the wiper.

As per the 68's owners manual the control under the dash that controls vacuum is the "manual control lever". The electrical switch used to stop the wipers on the windshield for service is the wiper "overide switch".

The manual control lever is used to open the wiper cover panel and keep it open for intermittent wiper operation.

The wiper overide switch should always be in the "OFF" position to prevent a electrical drain on your battery, left on it will discharge the battery.

[Joseph C.]

Re: 68 wiper motor question AGAIN!

The door will operate once I pull the over ride valve under the drivers side dash. But will not work when I turn on wipers??
Thks

[Paul O.]

Re: 68 wiper motor question AGAIN!

Joseph sounds like your vacuum solenoid on the back of your Tach has failed or the electrical connector is off or a bad connection. When you move your wiper switch to "ON" this then opens the port in the solenoid bleeds vacuum off your wiper door relay valve. That then allows vacuum to be ported to the open side of your wiper door motor.
Also I believe on a 68 there is no vacuum valve under the wiper grill Pass side that was installed 69 and later. Hope that helps. Paul 18046

[Terry B.]

Re: 68 wiper motor question AGAIN!

I'm not sure if this would apply in this situation but a number of the metal bezels that hold the wiper switch on the front dash become broken and do not ground the on and off switch. Be sure your bezel is not broken on the two narrow sides channels and if it is broken, it may not be grounded for a completed circuit.