shoemakerAM89
New member
- Joined
- Sep 17, 2025
- Messages
- 1
- Tractor
- John Deere 6400
I'm working on my JD 6400, problem is no 3pt lift control.
I've confirmed that manually activating the screw on top of the stepper motor will raise/lower the arms.
I've checked the wires that plug into the stepper motor for voltage, and I get no voltage when using the different switches that are supposed to operate the 3pt arms (quick up/down toggle switch in cab, wheel potentiometer, and remote switch under fender).
I've checked for voltage at the quick up/down toggle switch and I am seeing voltage there, and the voltage changes when I operate the switch. There are 3 wires that run to that switch, and the voltages vary from ~4.5 volts to ~1.5 volts. I would assume that this indicates the switch is operating correctly.
I've confirmed that the Hitch Control Unit under the cab is receiving power.
So, all that being said, it seems to me that the Hitch Control Unit may be the problem, unless anyone thinks there's something else I could test that would indicate otherwise. Is there any way to test the HCU itself?
I've confirmed that manually activating the screw on top of the stepper motor will raise/lower the arms.
I've checked the wires that plug into the stepper motor for voltage, and I get no voltage when using the different switches that are supposed to operate the 3pt arms (quick up/down toggle switch in cab, wheel potentiometer, and remote switch under fender).
I've checked for voltage at the quick up/down toggle switch and I am seeing voltage there, and the voltage changes when I operate the switch. There are 3 wires that run to that switch, and the voltages vary from ~4.5 volts to ~1.5 volts. I would assume that this indicates the switch is operating correctly.
I've confirmed that the Hitch Control Unit under the cab is receiving power.
So, all that being said, it seems to me that the Hitch Control Unit may be the problem, unless anyone thinks there's something else I could test that would indicate otherwise. Is there any way to test the HCU itself?
