Chevrolet Silverado

I have a 2003 Silverado 2500HD with approx. 74,000 miles on it. It has a 6.0 V-8. A few days ago the truck would not start. When you turned the key it just clicked. I checked the battery with a multimeter and the battery was low on voltage. I jumped started the truck and replaced the battery. Now the truck starts fine but has two noticeable problems. 1. The truck runs poorly at idle (in drive at a stop light for example. The RPM's are very slow at it will almost stall). 2. The A/C will come switch from blowing cold air to hot air and back again. This truck does have a two battery system. I thought the computer might make an adjustment to the RPM issue but it has not.
August 13, 2007.

You need to relearn the minimum idle speed. First make sure the throttle body is clean inside. Next disconnect battery neg cables for a couple minutes, then reconnect. Next apply park brake and block drive wheels. Next start vehicle, put in drive foot off brake pedal, and let it idle for 5 min. After that, put shifter in park and let idle 5 min. Then turn off ignition for 1 min. Finally, start the engine and drive to verify the repair.

Sep 29, 2007.
I was wondering if you were able to fix your issue with the idle probs you posted here. Did the solution Denny provided work? I ask because I have a Silverado and I am having the same problem. I tried the suggestion and yet I still have issues. Seems the local car repair place cant find why. Also, if you did get it fixed, do you still have the truck and are you interested in selling it? I need another one for my farm. Nothing pretty just functional.

Oct 31, 2008.