Grab yourself a techII scan tool. You will be able to see just about everything communicating electronically in the truck, on the techII. A lot better than just sorta parts cannoning stuff and hoping it solves the issues.
Nah, techII isn't neccesary these days. You can see a lot with a lot of things. Was able to confirm oil pressure is good in the computer, so confirmed the IC needs repaired. I'll be pulling that this weekend and sending it off to be pulled and customized I think i might rename this thread though, it's spun off into me rambling about all the various things i've been doing to the Denali.
Got the AC recharged, was able to gett the boss man discount on it since i ended up sitting there BSing and talking shop with the owner of the shop. Being a cummins guy, we were able to ride on one of his employees about the kids 02 Ram Cummins and the things that were right and the things the needed fixed. Plus talked about a bunch of other stuff. Always fun to get to BS and do some shop talk from time to time. Turns out the accumulator was bad too, so glad we replaced that along with the compressor to get the warranty on the compressor from Napa. Ice cold AC the entire way home, so i'm pretty happy about that.
This weekends i'll be pulling the IC out, installing a new radio (Jensen 110W from Crutchfield) swapping out the light switch (i've had a couple issues with it keeping lights on, figured for how cheap it is, i'll just throw a new one in) and then i'll be sending the IC off to get repaired on Monday. Also probably going to let it get some visual upgrades in the process because i'm bad with my money. Also ordered up new steering wheel buttons as most of mine no longer light up, and half of them are worn out to the point that they are more white then black. Part of the radio install will be adding a backup camera. So i'll have to debate between running it right in from the back like a lot of people do, or running it under the truck and up and into the cab using an existing gromet along the way. Also hoping to do some work on the truck this weekend too since the wife will be tied up elsewhere, i can work without interruptions. Guess i'll find out how far i get this weekend