2001 Ram A/C goes to defrost when i accelerate

hi, whenever I hit the gas or start going uphill, the a/c switches from the vents to the defrost on my windshield! I have looked around some on this issue and I found that it might be a vaccuum leak or a faulty check valve? my problem is that I have very little experience and detailed instructions on how to fix this problem would be much appreciated!! Thanks!

It usually means there may be a leak somewhere in the vacuum system. Those controls are run by vacuum and when you accelerate the vacuum is reduced. Yours is going down too far. A loose or cracked hose is likely.

This is a known problem with Chrysler products that were made over a fairly long period of time. Hopefully by now there has been a Technical Service Bulletin regarding how to repair this problem. Check with the dealer to see if there is a TSB for this known problem.

Detailed instructions for diagnosing and repairing things like this are found in a shop manual. Try Books4Cars.com, they might have one. You can also look in your local book store for a Haynes manual for your vehicle.

[b]A vacuum leak in the vent controls is the problem as mentioned. But also check the vacuum reservior and the check valve between the engine and the vacuum reservior.

The vacuum reservior holds a reserve of vacuum to prevent the vent system from doing what yours is doing. And the check valve to the reservior prevents the vacuum from bleeding off when engine vacuum is reduced.