Most electric pallet stacker problems fall into a handful of categories: it won't start, it won't lift, it won't stop, or it's showing a fault code. This guide walks through the common causes for each, in the order worth checking them — starting with what you can check yourself before assuming the machine needs a service call.
Before doing anything else: power down and read your machine's actual capacity plate and operator manual for model-specific detail. This guide covers general causes that apply across electric stackers; your unit's manual is the authority on your specific machine.
Table of Contents
- The Stacker Won't Start at All
- Contactor Works, But the Stacker Still Won't Move
- It Only Moves Forward or Only Backward
- The Stacker Won't Stop or the Brake Doesn't Work
- The Forks Won't Lift
- The Forks Won't Lower After Lifting
- Steering Is Stiff, Stuck or Noisy
- Reading Fault Codes on the Indicator Light
- Preventing Problems: A Basic Maintenance Schedule
- When to Stop Troubleshooting and Call for Service
The Stacker Won't Start at All
If the contactor doesn't engage — no sound, no response at all when you turn the key — check these in order:
- A blown control-circuit fuse. If it's burnt out, it needs replacing before anything else will work.
- The power switch or key switch making poor contact, or damaged.
- A blown main circuit fuse.
- The electric lock switch in poor connection or damaged.
- A loose or disconnected battery connection — check that the terminals are seated and tight.
A loose battery connection is the quickest thing to rule out and the easiest to fix yourself. A blown fuse is also a fast check if you know where the fuse sits on your model. Anything involving the switch or electric lock usually means a repair or replacement part.
Contactor Works, But the Stacker Still Won't Move
If you hear the contactor engage but the machine still won't travel, the fault has moved from the power circuit to the drive system. Common causes:
- The drive wheel's side-magnetic brake isn't releasing, leaving the machine in a braked state.
- Worn walking-motor carbon brushes, or poor contact between the steering device and the carbon brush.
- A broken or poorly contacted magnet-exciting coil on the stepper motor.
- A fault on the MOSFET-type circuit board.
Worn carbon brushes are a normal wear item and a fairly routine repair. A circuit board fault is not something to troubleshoot further yourself — that's a call-for-service situation.
It Only Moves Forward or Only Backward
This points to one of two things: the contactor is in poor connection or burnt out, or there's a malfunction in the circuit board. Neither is a DIY fix — this is a repair-or-replace situation for the contactor, or a service call if the circuit board is involved.
The Stacker Won't Stop or the Brake Doesn't Work
If the machine can't stop during travel — a moving contact that's broken and can't reset — cut power immediately and don't continue operating it. This is not a fault to work around; replace the contact before using the machine again.
If the brake itself isn't engaging, check:
- The fine-motion switch's mounting bolt — loose or damaged bolts here need adjusting, tightening or replacing the switch.
- The side-magnet brake's connecting wire, if it's loose or damaged.
- Worn braking plates on the side-magnet brake, which need replacing.
The Forks Won't Lift
This is the most common complaint, and it has the longest list of possible causes — work through them roughly in order of how easy they are to check:
- Insufficient battery voltage. Charge the battery and try again — this alone resolves a meaningful share of "won't lift" cases.
- Insufficient hydraulic oil. Add the appropriate filtered hydraulic oil for your climate and load.
- The control handle isn't in the correct horizontal or vertical position, or the oil pump motor hasn't engaged — this is often just an operating sequence issue, not a mechanical fault.
- Overload. Reduce the load to within rated capacity at your current lift height.
- The electric lock isn't unlocked or is damaged.
- The relief valve pressure is set too low.
- Internal abnormal leakage in the lifting oil cylinder, or a damaged oil pump.
- A damaged lifting button.
- Seriously insufficient voltage in an individual battery cell — this needs a recharge, and if it recurs, the cell may need attention.
The first three are worth checking yourself before assuming anything is broken. Relief valve pressure, oil cylinder leakage and pump damage are mechanical repairs. If you're new to what "capacity at height" actually means for your machine, the Electric Pallet Stacker Beginner's Guide covers pre-use checks and load limits in more detail.
The Forks Won't Lower After Lifting
This is a different problem from not lifting at all, and it's a more serious one to leave unresolved — a load stuck in the air is a safety issue, not just an inconvenience.
Possible causes include an overloaded and deformed internal or external mast, a dead mast roller, a curved mast guiding rod, a blocked oil return hole, or an electromagnetic valve that's out of control. A blocked oil return hole can sometimes be cleaned; the others — deformed mast components, a dead roller, a curved guide rod — are structural and need a technician, not a workaround.
Don't attempt to force the forks down mechanically. Lower the load safely if possible, secure the area, and treat this as a service call.
Steering Is Stiff, Stuck or Noisy
If the steering has gotten stuck, check whether the steering device's bearing is damaged (replace it) or whether it simply lacks lubricant or has accumulated dust (clean it — often the fix is that simple).
Difficult steering with noise and an overloaded-feeling motor usually traces back to a stuck gear or bearing from foreign material, a gap in bearing clearance that needs adjusting, or a damaged front wheel bearing that needs replacing.
Reading Fault Codes on the Indicator Light
Many electric stackers, including the CTD15R, use a status indicator light that flashes a fault code when the controller detects a problem. When everything is working normally, the light stays solid on. When a fault occurs, it flashes the code in a repeating pattern until the fault clears — and if multiple faults are present at once, only the highest-priority one displays.
A few of the most common codes and what they mean:
Most codes in the 1,x range trace back to power, throttle or battery issues — worth checking the simple stuff (charge level, connections) before assuming a component has failed. Codes further into the sequence more often point to something inside the controller or contactor that needs a technician to diagnose properly.
Preventing Problems: A Basic Maintenance Schedule
A lot of the faults above are more likely to happen — and happen sooner — on a machine that skips routine maintenance. A basic schedule:
- Daily: check hydraulic oil level and battery charge before starting a shift.
- Every 50 hours (roughly weekly): check brake clearance (should sit between 0.2mm and 0.8mm), clean dirt and debris off the turning gearwheel, and check for unusual noise when switching steering direction.
- Every 200 hours (roughly monthly): check the whole machine for abnormal wear, horn function, fastener tightness, oil pipes for leaks, and carbon brush wear on the driving, lifting and steering motors.
- Every 1,000–1,200 hours: this is when wear items like fork wheel bearings, hydraulic oil, and carbon brushes on the drive motors typically need replacing, not just inspecting.
If the machine sits unused for more than two months, clean it thoroughly, cycle the forks up and down a few times to check they're working normally, then lower them to the lowest position before storing.
When to Stop Troubleshooting and Call for Service
A few situations are worth flagging as "stop and call" rather than "keep troubleshooting":
- The forks are stuck in a raised position. Don't force them down mechanically.
- The brake fails to stop the machine during travel. Cut power immediately.
- A fault code keeps returning after you've checked the obvious causes (charge, connections, load).
- Anything involving the circuit board, contactor internals, or controller — these aren't practical DIY repairs even for an experienced operator.
If you're within reach of Raelon's Richmond or Edmonton locations, the team can diagnose the issue directly or arrange an on-site visit. Outside BC or Alberta, Raelon can help identify a local repair shop and cover eligible repair costs. Either way, describing the fault code (if there is one), when it started, and what you were doing when it appeared makes diagnosis faster on the first call.
For pre-use checks and safe operating basics, see the Electric Pallet Stacker Beginner's Guide, or contact the Raelon team directly if you're dealing with a fault that isn't covered here.
