Ok this is for those of you that have the vent problem, I did some looking on the threads and where most people are saying to put the check valve didnt work for me. I did some looking and the vacuum canister should probobly go over by the AC condensor. there are before and after pics attached.
(forgive the pictures they were taken with my phone)
Before:
After:

 

BTW this was all on the pass3enger side of my truck, there were two lines going up underneath the dash, I believe that they were both for the vents

 

If that fixes the problem on your model year it is good information.

Thanks for posting those pictures.

Besides the dealership some of the auto parts stores have that combination vacuum reservoir and check valve in the 'Motor Mite' brand replacement parts section

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I had ordered a replacement part from Dodge that is supposed to correct the
'Wild Vents' problem. This is where AC/Heat air blowing out vents
mysteriously changes and comes out other vents. It is most prone to happen
when accelerating. I read that the cruise control can suddenly 'pop out' of
setting too.

I haven't had the vents change wildly like that myself, but I have had the
'Defrost' setting refuse to work, then come on suddenly 10-15 minutes later.

Chrysler's 'Fix' is replacement part number 04677204.
I think there is a TSB on this.
I had seen the description of the problem in some automotive service
magazines.
My local Dodge dealer told me they now had the part, and I went and picked it
up (plus a broken passenger side sun visor clip). Cost was $7.84

The replacement part turns out to be about the size of a 35 mm Film can and is
a small vacuum reservoir with a built in check valve.
The original part (4306923) was a tiny check valve about the size of the tip
of my thumb. These check valves are in the vacuum line connected to the
nipple just rearward of where the PCV valve hose connects on the passenger
side of the engine. Just behind this check valve the vacuum line T's off that
goes to the cruise control mounted underneath the battery.

But when I went to put it on, I found that the new part lacked the proper
rubber hose fittings to install it. The new valve 4677204 has 3/16 nipples.
The new valve comes with only one rubber reducing elbow which has a female 3/8
end, and the other end 3/16 female.

The original check valve 4306923 has 1/4 plastic nipple ends and has a 1/4
rubber female elbow on one end, and short length of 1/4 rubber hose on the
other. The new valve's 3/8 rubber elbow is wrong - too big to seal to the 1/4
nipple at the intake manifold.

I went back to the Dodge parts counter to ask for the proper rubber fitting to
make it work, but they said they didn't have them and suggested I would have
to go to a parts store. At the local Advance Auto I could not find exactly
the right fittings, but was able to put the new check valve on using slightly
smaller fittings:

Motormite Mfg. Vacu-Tite! pn 47411 rubber elbow with 9/64 and 7/32 id ends,
and Motormite Vacu-Tite pn 47411 rubber straight with 9/64 and 5/32 id ends.

Seems sloppy on Chrysler's part - but maybe later model Rams than a 1995 have
different sized vacuum hoses and manifold fittings ?

 

I replaced my check valves as recommended and of course that didn't fix the problem. For you new guys, "the problem" is an uncommanded change of air distribution to defrost mode. The problem is most likely to occur when going up a long hill. I drive a hill that is about 14miles and over 2000ft change in elevation. I try to stay in overdrive, so I have a sustained situation where the throttle is open wide and the engine rpm is low thereby creating a low vacuum situation. If I let off the gas and coast for about 2 seconds the vacuum rises and cause the air distribution to return to the proper setting. The problem does not occur everytime I climb this hill. Only sometimes. It has happened in summer with AC on and also in winter with heater on. I haven't been motivated enough to put a vacuum gauge in the line yet, but that may happen in the near future.
Do you have a part # for the thingy in your picture?
Thanks for the info.

 

i have wild vents and no canister that looks like that... i have the T but no canister is that the part you put on ? if so where did you get it?

 

Yes that is a part I had to buy. It was chrysler's fix to the prbolem on those trucks. You can get the part at any Dodge dealership or your local oreily's might have it. If you get if from Dodge the part number is: 04677204 it costs like 7.50 real cheap. Then I went to an auto store and got a little peice of rubber hose to attach it to the line.

 

it would be my guess that putting a
2nd or even 3rd vacuum reservoir with its built in check valve in the system
would reduce further a 'Wild Vents' problem on the longest hill climbs

The vacuum T on the passenger side where Laramie1997 put his reservoir on
is only about a foot downstream along the vacuum lines
of where the Dodge TSB says to put it
at the vacuum nipple on the passenger side of the intake manifold
near the PCV nipple
at least on my 1995 Magnum 5.9V8

I don't see why a reservoir could not be put at both places to double up vacuum storage for getting through longer time periods where the engine is at low vacuum due to climbing hills or accelerating

However, it still makes sense to also thoroughly check for hidden vacuum leaks

 

I had to remove the origional vaccum cansiter from under the caL on my 98 ram it was a plastic one and cracked 3/4 around the seam. I put a metal on on the inner fender from another vehicle.
I tested the canister with a vaccum pump gauge. pressurized it to 2 psi and soaked it with soap and water and found the leaks...

 

I had the wild vents problem for a while, then the vents COMPLETELY stopped working. I could only turn on the defroster, or OFF. That is to say, no mattery which position I put the selector swtich in, it activated the defroster vents.

I just fixed it, after many hours of going through vacuum lines. Frustrating, all my check valves were operational, and the only leak I found was a disintegrated elbow-connector in the vacuum line under the battery (connects to the cruise control canister, I believe). Fixing this did not fix the problem though.

What was it? A LOOSE vacuum connector (multiple-line connector). The white connector behind the dash panel, that goes from the selector switch to the vacuum lines that pass through the firewall. (yes, those are vacuum lines, not electrical wires! It took me a while to realize that! ) I just unplugged the connector, and plugged it back in (took some real SQUEEZING to get it seated properly, all those gel-connectors inside of it that form a seal around the tiny little vacuum nipples inside the connector).

Now I can select defroster, dash, or floor vent. I don't know if the 'wild vents' problem is fixed though, until I drive it (that is, the problem of it changing vents while driving uphill).

I have a 2000 Dodge Ram 1500 Van. 5.2L engine V8.

 

While we appreciate the info, resurrecting a four year old thread isn't really necessary....