Hi,

I'm needing a Vacuum Diagram for 96 Ram Van.

I've got a some odd occurances with heating.
I get little to no heat from the heater, doesn't matter what settings (floor, vent, defrost).

I thought maybe engine was supercooled and needed new thermostat.
Wrong, thermostat was fine.

I believe it's with the vacuum system.
When I'm driving and put a load on the engine (going uphill), there seems to be a drop in vacuum pressure because the settings change from "heat" (floor) to "defrost" (windsheild).
Once the engine levels out, no load, the settings change back to where it should be.

I've noticed there is a vacuum valve from the engine coolant to the heater box.
I believe it's normally open, but unsure. It has one vacuum hose to activate, and spring to deactivate.
I cannot activate this from the settings control in the dash.

I've noticed there is a vacuum actutor at the heatbox itself.
It opens/closes a chamber, for what reason I do not know.
It has two vacuum hoses attached. One hose has vacuum.
I cannot activate this from the settings control in the dash.
I guess it is probably for fresh air, or re-circulate.
Above heaterbox, has a mechanical cable for the Hot/Cold, that opens/closes the chamber to the heating radiator.


There is vacuum from the engine, all the way to the vacuum ball.
The engine's idel is effected if the hose is removed.
There is a "T" from the hose from the engine to the vacuum ball, which travels to the heating controls in the dash.

I cannot find any diagrams to aim my trouble shooting.

Any help would be appreciated.
Thank you kindly,