OK guys...
On a 1970 Plymouth Air Grabber...It doesn't work...

Where do I start the diagnoses ?

Mighty-vac???

To use the Mighty Vac disconnect the hoses frome the actuator. Draw a vacuum on both sides, one to go up, the other to go down. If that works one of the first things I would check is the solenoid. If it does not have key on/run power it will bleed off the vacuum. For test purposes bypass it. I would also test for vacuum at the switch which should be deriving it from the canister. If you have vacuum at the switch and it's not the solenoid test for vacuum at the switch nipples. If no vacuum or very weak it is a bad switch which may be able to be fixed.

Have you hooked the actuator direct to manifold vaccuum and see if it works yet?

The closing relay could be stuck open. Listen under the dash for the giant sucking sound.

But, based on your past wiring posts, I'm leaning toward "you hooked it up wrong" If you don't hear it sucking air, there ain't much else can be wrong.

You might need the attached file. You'll have to zoom in on it I reckon.

Checked the actuator with a vacuum pump and it works.
Checked for "key-on" power at the solenoid and I have that.
What's next?

1 - ck for key on voltage at the electric solenoid. Should be 12 volts with key in run position.

2 - If ok, then with engine running ( or a substitute vacuum source ) ck for vacuum at the hose @ the airgrabber switch with the green stripe....should be engine vacuum .

3 - If ok, ck the hose @ the back of the switch with NO stripe and see if it has vacumm with it in the open position. If OK move forward.

4 - CK for vacuum at the same black hose at the solenoid , again should be engine vacumm if the swithc is in the open position.

5 - if the solenoid is doing it's job, there will also be vacuum on the hose with the yellow stripe to the vacuum actuator.

So with the engine running can I un-plug the hoses from the switch and "feel" or hear the vacuum ?

Right now there's no "sucking" sound inside the car anywhere.

The engine vacuum goes into the storage canister...Can I bypass the canister to eliminate that as a problem ? Will the system work without it?

I'm wondering now if this Hemi creates enough vacuum?
I'm hooked into a fitting directly on the back of the intake.

Quote:

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Can I bypass the canister to eliminate that as a problem ? Will the system work without it?

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Yes

Run a hose straight from the intake fitting to the hood mounted actuator, if it works. You have enough vacuum to operate the system, and your problem lies elsewhere.

if it doesn't, you either have low vacuum ( you ck'd it I assume ? ) or a bad actuator


If The car I just finished works it, yours should.
As it only takes maybe 5 inches or so of vacuum to operate the actuator. I assume you don't have a hand held vacuum pump?

First off Bill, thank you for your help...

I'm outta time tonight because of kids soccer...but here's what I've found...

Hooked the engine directly to the actuator and it works fine.

By-passed the canister and there's no difference.

Tomorrow I'll get under the frickin dash again...

What's the solenoid's job ? Can I by-pass it?

The solenoid bleeds vacuum when you turn off the key to lower the door. It will go down slowly unless you have the spring hooked up. That's the job of the spring, to assist in closing.
Some guys bypass the solenoid and leave the spring off so when the car is shut off the door will stay open.
Yes, you can by-pass it by either jumping the hoses with a nipple or run the hose from the canister to the switch if it will reach. You can use another nipple and extra hose if it doesn't. After doing this, if it still doesn't work pull off the other 2 hoses from the switch and using the Mighty Vac check for vacuum on both nipples while flipping the switch to the up and down positions. It should be the same as the vacuum coming from the canister. If not, there is a problem with the switch as I mentioned in my other response.
If it is low you can take the switch apart, I believe there is a gasket. You can buy individual parts or the whole switch to make the repair. Your welcome. Hope this helps.

This type of trouble shooting has been a GREAT help....

Info like this can't be found in any service manual.
I'll get on it again hopefully tomorrow, thank you.

Ok...The switch I bought brand new doesn't work..

I have an NOS chrome handled one and a nice used one.....
I guess you can put that switch in the aftermarket parts thread...

Well I'm 100% certain it's the switch.
I made a little jumper hose with two small metal tubes on each end.
With the system completely hooked up and the engine running I unplugged the switch. Using my new little tool I plugged into the green hose and white hose and the air grabber opened, then green to black and it closed, so I pretty much know it's the switch.
I bought it a year ago, but the company I bought it from said they will send a new one free of charge...