Ok new to the site lots of great info so I have a 770G motor grader S/N 1DW770GXTBE634381 fan goes to high speed does not come back down checked temp sensor shows good any one else had this problem don't see it listed on here .
Welcome to HEF John ! All the below sensors are inputs for fan speed. So any one of them or their wiring could send the fan to full speed. Also the solenoid that controls fan speed it's wiring can cause fan speed to run at maximum. Did you check for codes (active and stored)? Charge Air Temperature Ambient Air Temperature Hydraulic Oil Temperature Engine Coolant Temperature Transmission Oil Temperature Air Conditioner ON/OFF Status For example, unplugging any of the above sensors or the fan speed solenoid (think open circuit) will send the fan to full speed.
OK thanks checking wire harness today no codes present will check sensors also will post results