Most likely is the control wiring to the hydraulic solenoids out at the carriage.
The overmast cable (the one running through the mast channels), the cable that runs through the reach assembly ( h frame where reach rams mount) and the diode pack under the reach assy if it is equipped it should be if you have a 20I be careful of jumpers installed on the terminal strips if you are removing the wiring they are small pieces of steel that fall out after the screws are loose. Jumping power past the entire circuit can prove the wiring is faulty or not. Good luck. Don't chop your arms off.