My AC is running fine except I can hear a vent door close and then open again after a few seconds. When it closes the cool air stops until it opens again.
1997 Ram 1500

 

The check valve on the vacuum line my be going out.

 

yeah you might have two of those check valves and one of them may be shot...they are on the passenger side of the motor and in the vacuum lines!!!!...some of them are real tiny and some oem are bigger...just make sure it is faced the right way and the lines fit.....if that dont fix it then you probably have A VACUUM LEAK SOMEWHERE!

 

Thanks I will check them.

 

Cheap and easy fix really. There are 2 check valves on the passenger side of the motor. 1 sits right on top of the passenger valve cover (there is a Y adapter on this one, one side goes to the Cruise Servo across the top of the engine, the other goes right into the intake manifold). The other Check valve is up near the firewall, where a little T fitting connects 3 different vacuum sources.

I got 2 new check valves from O'reilly's for $8, swapped them out, instant fix.

Good luck!

 

I have random heat that comes through my vents, but sometimes I can't tell if it's just the heat from the dash, lol. Would replacing those check valves be a safe bet anyway?

 

It might help. I had a Buick GN Turbo that would do that randomly, and it was a heater valve (switch?) that had holes eaten through it, and it wouldnt block off the heat when you turned the selector to Cold.. Dont know if the RAM's have something similar.

 

Shoot, I noticed today it wont blow out of the dash vents, just out of the top and bottom vents. IDK to say it's stuck or if the Control Panel isn't functioning. Gr.

 

That is what happens when you don't have any vacuum at all. If the check valves don't fix the problem, I'd start looking for leaks.