I had the exact same problem after my engine pull. It seemed a wire ty broke and allowed the compressor wiring to short out against the front exhaust manifold when I turned on the AC or DEF. Look at the front of the car, near the radiator fan wiring to make sure everything has proper clearance.

http://www.bnmotorsports.com "And I will strike down upon thee with great vengeance and furious anger those who attempt to poison and destroy my CEG brothers. And you will know I am the Moderator when I lay my vengeance upon you."