97 Ram 5.2L Idle Problems & Questions

I have a 1997 Dodge Ram 1500 with the 5.2L V8 and automatic transmission. I've noticed some strange idle problems that I need some advice on.
My initial symptoms went like this:
Start the truck in the morning (cold) and put it in reverse. IDLE goes to about 1500 rpm.
When the AC is on the idle is high (1500 rpm) whenever the compressor cycles on. If I turn the AC off the RPM returns to normal.
When I rev the motor it's return to idle isn't smooth - it seems to hang at certain spots on it's way down.
This weekend I pulled the air filter box and noticed a small piece of rubber vacuum line on the front of the throttle body that was rotten and leaking badly. I replaced the hose and without the AC on things seem to be better, but I still have this RPM elevation when the AC compressor comes on.
Any advice would be appreciated.
Mark.
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Hi Mark, I have a 97 RamVan 5.9 L Camper/Van Motorhome which i just bought. When my a/c compressor kicks in , the motor stays at the SAME rpm as when i dont have the a/c on ; im not sure this is correct as every other vehicle ive owned , the rpms increase a bit to compensate for the additional load put on the motor when the a/c compressor comes on. I hope someone in this NG can tell us which is right.
Dave
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