03 avalanche power keeps on draining from some where.

reset the CPU program after the battery change out. Use a code reader for this process as the program is corrupted

sounds like the radio it's the problem. to make sure it is, you have to do what mechanics call a parasite circuit test, simply buy a test light at your local auto parts store, open the engine hood and look for the battery disconnect the negative cable and connect the test light in series with the battery and negative cable, the test light will stay on indicating that in fact there is a parasite circuit drain, find the fuse box your car comes with a owner's manual this manual it's helpful to find the fuses in the car, now that you find the fuses take out one fuse at the time until the test light goes off, (important put the fuse back before moving to the next one) when the test light goes off by removing the fuse, that is the circuit that it's draining the battery, check the fuse number whit your owner's manual to see if the radio in fact it's part of the fuse circuit. if not then you have a drain somewhere else in that circuit, (important the car doors must be close while doing this test or the interior light will stay on causing a normal drain keeping the test light on. and if the test light does not come on when connecting it in series don't panic this means the drain it's too small and then you have to do the same test but this time using an amp meter which it's more expensive and more complicate than the test light.

remove the positive cable from your battery then connect a test light in between the cable and the terminal of the battery. at this point it will be lit up. if you have an under hood light the bulb will need to be removed as well as the radio fuse and unplug any thing from the cigar lighter. remove the dome light fuse. if the test light is still lit up then you have a parasitic drain. the first thing i would do is remove the large red wire from the back of the alternator as a shorted field is the most common form of parasitic draw, if the test light is still on and are sure that everything is off and unplugged then start removing fuses one by one while checking if the test light is still on. once the test light goes off then you have found the circuit that is causing the draw. repair will depend on the circuit

You have a parasitic draw on the battery , Testing to find the draw isn't too hard ,all you need is a DMM - digital multi-meter . Test for voltage drop over the fuse's . I know GM vehicles had instrument cluster problems that would cause this problem , but test first . Watch these videos .
The BEST Way TO Perform Parasitic Draw Test
Chevrolet Truck Battery Dies Overnight Part

are you leaving anything plugged in, cellphone charger, radar dector, emergency lights, cb, etc, if so unplug all of it that will kill the battery, if not the case, you got a short somewhere

INTERMITTENT BATTERY DRAINS ARE HARD TO FIND. TURN OFF ALL SWITCHES IN THE VEHICLE. MAKE SURE THE GLOVE COMPARTMENT LITE IS GOING OUT. OPEN THE HOOD. CLOSE ALL THE DOORS. MAKE SURE ALL OF THE COURTESY LITES ARE GOING OFF. DISABLE ANY UNDER THE HOOD LIGHTS. REMOVE THE NEGATIVE BATTERY CABLE. USE A 12 VOLT TEST LIGHT, FASTEN ONE END TO A GOOD GROUND, { METAL PART OF THE MOTOR} . FASTEN THE OTHER END TO THE NEGATIVE TERMINAL OF THE BATTERY. IF THE TEST LIGHT LIGHTS UP THERE IS A BATTERY DRAIN. IF NO LIGHT , NO DRAIN. IF THE LIGHT IS ON LOOK IN THE FUSE/RELAY BOX NEAR THE BATTERY. PULLOUT THE FUSES, LARGE & SMALL ONE AT A TIME, IF THE LIGHT STAYS ON PUT THE FUSE BACK IN TRY THE NEXT FUSE. WHEN THE LIGHT GOES OUT, THAT IS THE CIRCUIT CAUSING THE DRAIN. IF IT NEVER GOES OUT, DISCONNECT THE ALTERNATOR. IF THAT MAKES THE LIGHT GO OUT, THERE IS SOMETHING WRONG WITH THE ALTERNATOR. IF THE LIGHT IS NEVER ON, YOU MAY HAVE TO DO THIS ANOTHER DAY TO FIND THE DRAIN. ALSO HAVE THE BATTERY RECHECKED.

Well if lights are not staying on then you have a draw of power somewhere. Easy way to find out is volt meter. You take off negative cable and put one end of meter to battery post and other to wire dont let the wire touch post or anyother metal of vehicle. Then go through your fuse box and pull fuse's one at a time until you see voltage on meter drop. Meter should should a (-)negative voltage at start and get smaller when right fuse is pulled take notes and pull all one at a time and replace back in orginal spot. If you find one that really lowers the negative voltage draw on meter good chance you found where problem is. Id start by checking all interior lights first, including glovebox.

The ABS modual has gone bad. You can pull the ABS maxi fues under the hood to keep it from killing your battery.

Apparently the 03 wranglers have a tendency to have faulty fog light switches. It might be that your fog light switch is broken and they stay on all the time, and drain the battery. I just had this happen to me and realized after jumping it twice, that my fog lights won't turn off. Hope this helps

Check the light under the hood, the switch may be bad and the light stay's on all the time and over the visor. Check to make sure the vanity light is off also.  It's just a start and i have known also that the 4X4 actuator will drain too. Keep me posted, be glad to help and it sounds like it's going to be a gremlin to find the battery drain.