1996 Dodge 1500 van swb v6. Is there a schematic for the vacuum lines and actuators in the climate control system? There is a vacuum leak. If you look at the plastic lines they shatter. Rock Auto for the lines? There is a vacuum problem going up hills where it drops enough to disengage actuators controlling the ac system in the summer. Low compression would also suggest low vacuum. Put a vacuum gauge on the truck when operating under load?

He tested the compression on the v6. With his old tester it read 95 on all cylinders. I'm going to lend him mine which is a few decades newer.

I believe the previous owners swapped out the instrument cluster, because no way this thing has 111k miles with all the problems it has had.

Can someone please point me in the direction of the schematic. Are they available on the paid subscriptions? Will a FSM have it? The are $50 on e bay. It's a good friend's truck, and I'd like to help him out.

 

Factory service manual will have 'em.

Vents going to default when engine load is high isn't unusual. Vacuum holds the various doors in place, if there is no vacuum, the doors revert to their default positions. Usually, what happens is a check valve fails, or, there is a vacuum leak in the system somewhere.... And yes, the plastic lines in the engine compartment do indeed age, get brittle, and if you even look at them wrong, break. You can patch 'em back together with appropriate sized rubber line from your local parts store. Or, replace them entirely......

 

Schematic found in my search last night. It's a 94. https://www.vanning.com/threads/ubbt...eleration.html
Could someone add a sticky for that reference?
A mighty vac shows leaks in some of the lines. The colors of the lines change midway. This is where numbered tape, or Dollar store nail polish comes in. Ya know, back in the days of timing lights? This thing has been patched together with flex vacuum line in many places. Where it goes thru the firewall is a cluster. Did not consider check valves failing.
?Are the check valves supposed to prevent sudden depressurization if a low vacuum condition is encountered? Or just ensure a one way flow? Are the check valves separate from the actuators, is the default position closed, are they spring loaded?
Using a smoke machine on it did not work, ?perhaps because the leaks were too small, the line wasn't flexing to open cracks, or the check valve prevented flow?
He purchased the super duper smoke with a uv dye in it, and other than being quite pricey, and very stinky, I didn't see the value this time. Much nastier in a closed area than baby oil or mineral oil.
If we were to smoke it again? I guess we would have to start at an actuator, see if is leaking, and work backward toward the source of the vacuum. One actuator at a time?
We are going to t it off and have a vacuum pressure when running. . He has two other dead parts vans, so odd pieces can be had.

Thanks for getting back.

 

A sticky with a link directing people away from here to another van forum...perish the thought!

 

Mighty vac showed that there was a leak. Turned out that an actuator diaphragm was broken. Thanks for the help.

 

thanks for the update


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