JD4300 gas and temp gauge not working

[MACrook]

JD 4300 gas gauge is pegged and so is temp gauge, but rpms work and hour meter. Is it most likely the sending units on gas and temp or the cluster. I understand the cluster for these models is finicky and has known issues. TIA

 

[Roadworthy]

Try to score an electrical schematic for your tractor. Some vehicles use a separate lower voltage instrument regulator for the fuel and temperature gauges. It is about five volts. If it's shorted internally that could certain cause needles to peg.

 

[WranglerX]

Typical of a lot of gauge systems is for them to go full scale (pegged) if there is an open circuit between gauge mechanism and its sender.... You need to trace wiring from dash panel to sender to see if there is a disconnect or loose or dirty plug/socket.....