Troubleshooting Electrical Failures in Waldon Bucket Trucks

[MikePhua]

The Waldon Legacy and Transition to Utem
Waldon Equipment, once a respected name in compact industrial vehicles, produced a range of utility trucks and loaders throughout the 1980s and 1990s. Among their specialized offerings was the Waldon bucket truck—a compact aerial lift vehicle designed for utility maintenance, signage installation, and tree trimming in urban environments. These machines were known for their rugged simplicity and ease of service, often favored by small municipalities and independent contractors.
By the late 1990s, Waldon’s bucket truck division was absorbed by Utem, a company specializing in aerial lift systems and utility vehicles. While Utem continued to support legacy Waldon units for a time, documentation and parts availability became increasingly scarce as production shifted toward newer models. This transition left many owners of 1990s-era Waldon trucks searching for service manuals, wiring diagrams, and technical support.

Common Electrical Control Failures
One of the most frequent issues reported with older Waldon bucket trucks involves failure of the boom’s side-to-side and telescoping functions. In many cases, the joystick switches test functional, and the base controls operate correctly, yet the boom remains unresponsive. This points to a breakdown in the electrical relay system or signal transmission between the joystick and hydraulic actuators.
Typical causes include:

• Failed relays or solenoids in the control circuit
  
• Corroded or loose wiring harness connections
  
• Blown fuses or degraded circuit breakers
  
• Grounding faults due to frame rust or poor bonding
  
• Joystick signal degradation from worn contacts
  

These trucks often use 12V DC control systems with relay banks mounted near the base of the boom or inside the operator console. Over time, exposure to moisture, vibration, and UV degradation can compromise insulation and contact integrity.

Locating and Testing Relays
To diagnose relay-related failures:

• Identify the relay bank using the truck’s electrical layout (if available)
  
• Use a multimeter to test voltage at the relay input and output terminals
  
• Listen for audible clicks when the joystick is actuated—no click may indicate coil failure
  
• Swap suspected relays with known-good units to confirm diagnosis
  
• Inspect relay sockets for corrosion or heat damage
  

In one case, a technician in Pennsylvania discovered that the boom’s extend/retract function had failed due to a melted relay socket caused by a loose terminal. Replacing the socket and relay restored full functionality.

Joystick Switches and Signal Path Integrity
While joystick switches may test functional in isolation, signal degradation can occur along the wiring path. Older Waldon trucks often used non-shielded wire bundles routed through metal conduits. Over time, insulation can crack, and wires may short against the chassis or each other.
Recommended steps:

• Trace wires from joystick to relay bank using continuity testing
  
• Inspect for pinched or abraded sections near pivot points and entry grommets
  
• Replace brittle or discolored wires with marine-grade tinned copper replacements
  
• Use dielectric grease on connectors to prevent future corrosion
  

A contractor in New Brunswick restored his 1990 Waldon’s boom controls by replacing three feet of wire that had been chewed by rodents during winter storage.

Service Manual Challenges and Workarounds
Finding a service manual for a 1996 Waldon bucket truck can be difficult. Utem may refer owners to regional dealers, but many no longer stock documentation for legacy models. In such cases, operators have resorted to:

• Reverse-engineering wiring diagrams from existing circuits
  
• Comparing components with similar-era Utem trucks
  
• Joining online forums and user groups to share schematics
  
• Creating custom labels and diagrams during repairs for future reference
  

One operator created a laminated wiring map for his truck after tracing each wire manually. This map now hangs inside the cab and has saved hours of troubleshooting.

Lubrication and Fluid Specifications
Beyond electrical issues, maintaining proper lubrication and fluid levels is essential for safe boom operation. While exact specs vary by model, typical guidelines include:

• Hydraulic fluid: ISO 46 or AW32, depending on climate
  
• Boom pivot grease: Lithium-based NLGI #2
  
• Gearbox oil (if applicable): SAE 80W-90
  
• Electrical contact cleaner: Non-conductive aerosol type
  

Lubrication points should be serviced every 100 operating hours or monthly, whichever comes first. Neglecting these intervals can lead to binding, increased wear, and actuator failure.

Safety Considerations During Diagnosis
When working on aerial lift systems:

• Always lower the boom and disconnect battery power before servicing
  
• Use insulated tools when probing live circuits
  
• Wear eye protection when testing hydraulic components
  
• Avoid bypassing safety interlocks unless absolutely necessary for diagnosis
  
• Document all changes to wiring or control logic for future reference
  

A technician in Ohio suffered a hand injury when a boom unexpectedly moved during relay testing. The incident led to a company-wide policy requiring lockout-tagout procedures on all lift equipment.

Conclusion
Waldon bucket trucks, though no longer in production, remain valuable tools for utility and maintenance work. Their electrical systems, while simple by modern standards, require careful attention to relay logic, wiring integrity, and joystick signal paths. With patience, methodical testing, and a bit of ingenuity, operators can keep these machines functioning safely and reliably—even decades after their manufacture. Whether trimming trees in Pennsylvania or repairing signage in New Brunswick, the legacy of Waldon lives on through the hands of those who maintain them.