I am trying to come to terms with whats wrong with my vacuum hose set-up after previous owners' mechanic had a go at it. I've got the ZIP vacuum guide but it doesn't explain clearly what hoses are supposed to be connected to the fittings on the passenger side wiper arm. There are three fittings on the arm and it appears that one from the dash (white I believe) is connected to one and the hose from the actuator relay (the small fitting on the end) is hooked up to the middle (red) fitting and nothing is hooked up to the other end fitting (closest to the wiper arm), although today I capped it off in case it was a vacuum leak.

The Zip guide looks like the one from the dash should go all the way to the wiper actuator relay and mine does not. Perhaps the wiper arm fitting serves the purpose of this "connection" although not sure why.

Finally, the washer hoses. The one from the center of the pump goes to the top of the washer container. I must assume the other two hoses go to the left and right side washer fittings that are part of the "cowl vent" that screws in next to the wiper door. My washer doesn't work anyway but wanted to be sure it wasn't hooked up wrong as well. Is there any vacuum in the washer operation or are the two unrelated?

I know my wiper switch is bad and have one on order. I haven't taken it apart yet. Is there a vacuum fitting and hose connected to the switch or is it just electrical wiring at that point?

Many thanks for anyone who cares to tackle these somewhat basic ( but not to me) questions!!!

Regards, Mark :flag :chevy

 

The wiper switch controls a solenoid that should be mounted behind the dash. This solenoid switched the vacuum on the wiper door. When the wiper door opens, it contacts the safety switch mounted in the engine bay. Finally, this switch completes the circuit for the wiper motor. The solenoid behind the dash is hard to find, both in the car and as a spare part. As far as a diagram, the best one I've seen came with the new hose kit I bought from Vette Products of Michigan. I don't have an easy way to post it, but I can explain it to you over the phone. Also, there a few good diagrams on the net.

Good luck.

Email me if and we get together on the phone if you like.

 

I'm not where I can look at my car, but for sure, one of the hoses coming from the valve under the RH wiper arm is a vent; it connects to nothing and should not be plugged. The purpose of that valve is to tell the system the wipers are parked and its OK for the door to close. The vacuum system has nothing to do with the windshield washers.


[Modified by JSB69, 3:09 PM 1/24/2002]

 

I am trying to come to terms with whats wrong with my vacuum hose set-up after previous owners' mechanic had a go at it. I've got the ZIP vacuum guide but it doesn't explain clearly what hoses are supposed to be connected to the fittings on the passenger side wiper arm.

I assume you're talking about the wiper interlock on 69-72 cars. It prevents the wiper door from closing until the blades are parked in the down position.

There are three fittings on the arm and it appears that one from the dash (white I believe) is connected to one and the hose from the actuator relay (the small fitting on the end) is hooked up to the middle (red) fitting and nothing is hooked up to the other end fitting (closest to the wiper arm), although today I capped it off in case it was a vacuum leak.

Bad idea. The one fitting is a vent and should remain open.

The Zip guide looks like the one from the dash should go all the way to the wiper actuator relay and mine does not. Perhaps the wiper arm fitting serves the purpose of this "connection" although not sure why.

You've probably got a 68 diagram, without the interlock. Check out the following link. http://vetteworks.tripod.com/techdocuments/Vaccum.html

Finally, the washer hoses. The one from the center of the pump goes to the top of the washer container. I must assume the other two hoses go to the left and right side washer fittings that are part of the "cowl vent" that screws in next to the wiper door. My washer doesn't work anyway but wanted to be sure it wasn't hooked up wrong as well. Is there any vacuum in the washer operation or are the two unrelated?

I know my wiper switch is bad and have one on order. I haven't taken it apart yet. Is there a vacuum fitting and hose connected to the switch or is it just electrical wiring at that point?

The switch may not be bad. Check to make sure the center instrument panel is grounded. The switch gets its grounding through the panel. The switch is only electrical. The vacuum control is via a solenoid under the dash attached to the tach.


Many thanks for anyone who cares to tackle these somewhat basic ( but not to me) questions!!!

Good luck,
Gary

 

Thanks to all that replied. I'll start with your suggestions. This is such a great Forum!

Regards, Mark :chevy