On this model tractor the SAM mod is protected by a pigtail wire harness with a relays and diode in. Its plugs in on the right side, by the engine and goes to the PTO clutch. Replace it and relay! Does it make a big bang when you tray to start it again? I lost 70% of my hearing on 2166 and near blew the muffler of one.
Replace pigtail wire harness.
Replace pigtail wire harness.