Dead Battery Issues - '04 Yukon

bblair1

It was 14 months ago I found my (new) battery would not crank the engine. I connected an ammeter between the negative terminal and the cable and pulled ALL (about 100) fuses and relays, individually, to identify the drain. Three fuses were identified: radio, radio amp and info. totaling 3.0 amps . After recharging the battery I took the truck to a dealership for repair. After a week I was told the problem was the radio because: "It started after leaving over the weekend with the radio fuse pulled." I was charged $100. for this "help" and was told to replace the radio for a cost of $482.00. Instead, I pulled the radio and disconnected the plug on the unit that feeds the phone (OnStar). This seemed to fix the problem until now, 14 months later and the same condition repeated.
This time I monitored the drain for a longer time and found after about 1 minute the current dropped to 0.01 amps. with all fuses in place. Conclusions: 1. The whole diagnosis was wrong. 2. Something random is causing the BCM current to NOT reduce as it should after shut down. 3. The Service tech. people don't know how to deal with the products they are paid to service. Currently, the battery is holding it's charge but I expect it will let me down any time without warning. I have installed a battery disconnect for long idle periods and plan to monitor charge condition regularly and use a float charger.
I have searched the internet for any solution without success.....Any suggestions?