06 gmc 2500 hd auto climate control inop

[srbugsalot]

i have an 06 gmc sierra with auto climate control and have disconnected the battery. after hooking the battery back up the auto climate control head unit does not display anything. checked all fuses and found ok. checked connectors at back of unit and found ok. replaced the head unit and still will not work. do these head units have to be programmed before being replaced? any ideas? not ready to take it to the dealer cause i have a banks programmer on it and not ready to rip it all off the truck to bring it in.

[2004Yukon]

i have an 06 gmc sierra with auto climate control and have disconnected the battery. after hooking the battery back up the auto climate control head unit does not display anything. checked all fuses and found ok. checked connectors at back of unit and found ok. replaced the head unit and still will not work. do these head units have to be programmed before being replaced? any ideas? not ready to take it to the dealer cause i have a banks programmer on it and not ready to rip it all off the truck to bring it in.

Was the A/C on when you D/C'd the battery? If so, then you need to give it a couple of start cycles to reset itself. My 2004 did the same thing the first time I unhooked the battery. The next time you need to D/C the battery, make sure all of the accessories are off- A/C, dome lights, radio, etc...