For this job, I did a super tune up. Customer has a heat pump. Suggested IAQ for the mold and possibly new filter (April air/electrostatic.) The drain line has a restriction on the primary, I suggested they get it cleared and add a pan strip. At the outdoor unit, it is DC Inverted, As such I didn't check for inrush, etc.... When I went to wash the coil I pulled out the disconnect and half of it remained in the box. I immediately let the customer know that their disconnect had failed and needed to be replaced. Finished cleaning the coil, Left the disconnect unplugged, and turned off power at the electrical panel.