Table of Contents
Advertisement
Troubleshooting
4
Troubleshooting
4.1
Causes of malfunctions
There are three categories of issues that can lead to a malfunctioning tail lift: electrical, hydraulic and mechanical.
Electrical issues are fairly common and include but are not limited to damaged wiring, sensors, magnets and
solenoids. Control card failures also fall in this category but are very rare in normal circumstances. Hydraulic
issues include stuck or damaged valves and other oil flow obstructions or leaks within the hydraulic system.
Mechanical issues include bent, seized or damaged structural components and are the least common of the
three and the most easily detectable.
4.2
Troubleshooting strategy
Since the control card is a central part of the system and is responsible for turning the input signals into usable
output signals which drive the desired function of the tail lift, it is the best starting point for the troubleshooting
process. Following the steps listed below when troubleshooting is recommended.
Step 1: Control card power
Is the card powered on?
No: there is an issue with the power supply to the card. The fuse on the power cable to the card might be
tripped or the wiring is damaged or disconnected.
Yes: the card is powered on, proceed to next step.
Step 2: Control device inputs
Is the card indicating the correct control device inputs as shown in the functional description?
No: there is an electrical issue with the control device or with the wiring between the device and the
control card.
Yes: the card is receiving the correct inputs, proceed to next step.
Step 3: Sensor inputs
Is the card indicating the correct sensor inputs as shown in the functional description?
No: there is an electrical issue with a sensor or with the wiring between the sensor and the control card.
Yes: the card is receiving the correct inputs, proceed to next step.
Step 4: Outputs
Is the card indicating the correct outputs as shown in the functional description?
No: there is an issue with the control card. It might be damaged or of a wrong configuration.
Yes: the card is sending the correct ouput signals but there is
a) an electrical issue such as a damaged magnet, solenoid, motor or damaged wiring to those components,
b) a hydraulic issue such as a stuck valve, a leakage or an obstruction of the oil flow or
c) a mechanical issue such as a stuck, bent or in other way damaged structure.
Note that the troubleshooting steps listed above require the tail lift to be powered on and the cabin switch (if
present) to be in the "ON" position. If the tail lift is completely dead, use a multimeter to troubleshoot the power
supply starting at the tail lift and moving towards the battery. Possible causes include but are not limited to a
dead battery, a tripped fuse or disconnected or damaged power and/or ground cables.
36
www.zepro.com
Advertisement
Table of Contents
