i have a 2002 dodge ram van,,v8,,5.2 ,318 motor, but i have problems with the

[mrlove_21]

transmission, when the a/c is on? if im driving with the a/c off, there is no problem,, but when im driving around for a while and i turn on the a/c,,, the transmission wount shift properly so i have to manually shift it,,, and its an automatic..does anyone have or has had a problem like this...please help...and if possible dont tell me that the best bet would be to go to a mechanic,, cuz i know that,,,,what i want is to save a bit on the first trip and have an idea of what hte problem could be,,,any help is appreciated....thanks