I had my unit serviced last week. It included taking off the walls and top of the compressor unit and hosing it out with a cleaner. After he put it back together, I noticed that the fan on the compressor unit outside is now constantly on. The compressor is not on, just the fan blades keep circling. I checked and yes, the unit inside is completely off. I presume this is an easy fix, just a wiring mistake when he put it back together? It is a TRANE unit.