Yes we have ceiling mounted controls. I accessed every panel that I could find including everything on the roof to make sure all wires were secured. I’m not sure specifically where the thermostat wire connects but I will continue to look. What I can say is there is a harness that plugs into the ceiling assembly directly. That harness runs up to the top unit. I disassembled the entire top unit to trace those wires and they all run either through the capacitors or to the fan motors etc. Is there a place on the indoor unit other than that harness connection I should check?