Ok guys i know there is a part that gos wrong on a dodge i have a 99 dodge ram with the 5.9 liter with air conditioning, and when i keep my foot at the same place for like 10 seconds my air goes to my defrost but this doesnt happen when i use cruise control

 

The check valve on the vac line for your hvac is shot dodge replaced the valve with a bigger one which can be obtained at the dealership. It is the one next to the pcv line on your intake it has a little pancake valve on it. Or you can prolly get another regular check valve at any parts store.

 

OK well my truck does not have a/c, it does this with the heat??? Same issue?

 

Yep, it seems to be a common problem. When I can find my phone I will take a pic of the replacement I got from Dodge. I cant rember but I think there was a T.S.B. out for this.