Let me guess, your out there because the other guy would not come back to fix the no heat call? One visual look and that surly looks like a refrigerant leak on the vapor line (leaked faster in the heat mode). Other guesses, no vacuum before start-up, original old fuses, indoor coil was not replaced, screws missing on door panel (looks like 2 is good enough), equip is not elevated 2" per code, equipment blocks access to disconnect, I am surprised the whip is clamped to the wall must be the original work.