New Holland NH 1063 – EDC (Electronic Draft Control) / Hitch Controller: EDC Hydraulic Valve Lower Solenoid Open Circuit

The electronic control module has detected a break (open circuit) in the electrical circuit that powers the solenoid valve responsible for lowering the rear hitch via the Electronic Draft Control (EDC) system. Because the circuit is open, the controller cannot send the electrical current required to actuate the valve, preventing the hitch from lowering.

• T5.95
• T5.105
• T5.115
• T6010
• T6020
• T6030
• T6040
• T6050
• T6060
• T6070
• T7 Series
• T8010
• T8020
• T8030
• T8040
• T8050
• TM150
• TM175
• TS100
• TS115
• 5640
• 6640
• 7740
• 7840
• 8240
• 8340
• TG Series
• TJ Series

1. 1

   Visual Inspection: Inspect the wiring harness and connectors leading to the EDC hydraulic valve block (typically located at the rear of the tractor near the rockshaft/hitch assembly). Look for broken wires, chafing, or disconnected plugs.

2. 2

   Solenoid Coil Testing: Disconnect the electrical connector from the lower solenoid. Use a multimeter to measure the resistance (Ohms) across the solenoid coil pins. An "open circuit" fault usually indicates infinite resistance, meaning the internal coil winding has broken and the solenoid must be replaced.

3. 3

   Harness Continuity Testing: If the solenoid tests within normal resistance specs, check for continuity in the wiring harness between the EDC controller and the solenoid connector to rule out a broken wire in the chassis harness.

4. 4

   Voltage Check: Verify that the controller is sending the correct voltage (usually 12V) to the solenoid connector when a "lower hitch" command is initiated from the cab.

1. 1

   Preparation

   Ensure the tractor is turned off, the parking brake is engaged, and the battery is disconnected to prevent electrical shorts. Ensure the rear hitch is fully lowered and mechanically supported so it does not drop unexpectedly.

2. 2

   Locate the Valve

   Locate the EDC hydraulic control valve block at the rear of the tractor.

3. 3

   Disconnect

   Unplug the electrical connector from the faulty lower solenoid.

4. 4

   Remove the Solenoid

   Remove the retaining nut or screws holding the solenoid coil to the valve cartridge. Slide the old solenoid coil off the valve stem. (Note: If the entire cartridge is faulty, unthread the cartridge from the valve block, being prepared to catch a small amount of hydraulic fluid).

5. 5

   Install the New Part

   Slide the new solenoid coil onto the valve stem and secure it with the retaining nut.

6. 6

   Reconnect

   Plug the electrical harness back into the solenoid. Reconnect the battery.

7. 7

   Calibration

   Clear the fault codes. Crucial Step: After replacing EDC components, the system often requires a calibration routine. You may see a prompt (Code 1024: Perform Hydraulic Lift Autocalibration) which must be completed for the hitch to function properly.