I was getting an error stating “Printer stopped due to errors. Extruder switch off Max Temp triggered.”
I tested the thermister at the connector, it read 120K at room temp. Tested the thermister at the connector for the Rambo board, it read as an open. Noticed the wiring colors were different, swapped connectors at extruder, all better.
TL;DR: When you switch the extruder stepper motor connector and the thermister/hotend heater connector you get a max temp error.