ilk

Keeping your equipment up and on the road is priority number one.  When using our troubleshooting guide with assistance from our dedicated technical service team, you can feel confident that your liftgate will be repaired correctly and in a timely fashion. 

Initial Checks

NOTE: Please always use a digital voltmeter when checking voltage to determine if you have enough power to operate the liftgate.

Liftgate with Platform down on the Ground and won't go up

• Cross both large posts on the motor solenoid with the bar or screwdriver, making the motor run. This should make the platform lift, and once the platform is at floor level, keep the motor solenoid jumped (motor running), pushing down on the pin inside the S5 valve to make the platform close.

The Liftgate Motor will not run because the Thermo Switch does not supply Ground to the Motor Solenoid.

• How to Temporary Bypass Motor Thermo Switch

Before doing 10-10 test :

1. Shut off the truck engine
2. Unhook the charge coil from the tractor
3. Shut off the battery charger
4. Disconnect any outside battery source

Confirming battery voltage with 10 -10 test :

1. Using a multimeter, set on DC voltage
2. Attach the volt meter negative to the negative post on the motor
3. Attach the volt meter positive to the positive post on the motor
4. Using the lift switch, raise the platform to bed level
5. Keeping the switch activated, deadhead the motor
6. Keep the switch activated for ten (10) seconds and observe the multimeter reading

• Ten ( 10 ) volts for ten (10 ) seconds is the desired result
  • If the reading is less than eight ( 8) volts, the batteries are low and need to be charged
• Retest after charging
  • Replace batteries and check all connections and grounds if you cannot get 10 -10

Note: While doing the 10-10 test,  other lift gate movements will indicate a hydraulic problem 

Liftgate Not Working

Motor not running

1. Jump across large posts on motor solenoid
   1. If the motor runs, test for incoming signal on the small terminal and ground on the other small terminal
   2. Test the thermo switch in the motor for continuity if the signals are good, replace the motor solenoid
2. Jump across large posts on  motor solenoid
   1. If the motor does not run, jump the motor directly with jumper cables from a separate good battery
   2. If the motor is not running, tap on the motor; if the motor runs, the brushes are bad
   3. If the motor runs, check the motor ground and power to the motor solenoid

Truck: Turn on the cab switch

Trailer: Turn on the switch at the liftgate

• Check the fuse and circuit breaker at the battery
• Check fuses at the PC board
• Unplug these 3 connections on the PC board:
  • J-31 Hand Control
  • J-3 Warning Lights
  • J-41 x 2 B-13 and B-15 sensors
• M control—check fault codes
  • Clear the code: unplug J-11 and J-1 then plug back in
• Remove the J-30 plug, confirm #4 pin has voltage, jump #4 to the next 4 pins to get up, down, tilt down, tilt up, note last pin is ground, do not touch with the jumper on the J-4 pin

Emergency Operation: #E mode—emergency by-pass of sensors

• Turn and hold both down and tilt down knobs for 10 seconds until E code is shown
• Operate liftgate in E mode
• To reset turn the liftgate OFF and then ON

Liftgate Not Lifting

• Motor not running: see section above

Liftgate not lowering

• S-1 and S-2 valves on lift cylinders not opening

Liftgate not tilting up

• S-5 valve on the motor not energizing along with the motor

Liftgate not tilting down

• S-3 and S-4 valves on lift cylinders not opening

Liftgate not lifting load

• First, add a 12-volt power supply direct to the batteries
• Second, move the 12-volt power supply directly to the motor solenoid and ground it on the motor
• Adjust PSI to 3000 PSI
• Change hydraulic fluid to fluid ISO 32