if you have 0 psi in the low side, then you have 0 psi in the high side. sounds like you definately have a leak. since you have a chrysler, it probably has a/c tracer dye in the system from factory. look around for a sticker that has a/c system info on it, that will tell. if it does have dye then you can look for the leak with an ultraviolet light and some yellow tinted glasses. the dye will glow green under the light.
be sure to check the evaperator core drain tube for dye, that is the mose likely place on a Jeep.
if your truck doesnt have tracer dye, you might have to go to a shop to get some put in with some freon. some shops put a warranty on the freon with the dye. so if you fix the leak with them, they will fill the system back up with freon at no charge. the is a real plus, so shop around for a good place to go.
