Digital lights, heater, blower, A/C quit.

Digital lights, heater, blower, a/c quit working all of a sudden. I was told by a caddy mechanic on line to change the body control module. Got one from a1 cardone no change. Called and talked to them. Got a second one from them put that one in. No change. The digital lights, blower come on when car is first started then the things mentioned go out about 10 seconds after. Everything just fades away. Now I am being told to change the electronic climate control programmer. Does this sound right. Car only has 31117 original miles on it. One owner. Car is like brand new always garaged. Car has good charging system and every fuse lights up bright with a test light except number 4 fuse on the relay center which says blower but the blower comes on when first started along with all the green digital lights. Then everything fades away like you are turning a dimmer switch. Can anyone figure this car out. Any info would be great. Iam at my wits end with this car. HELP