CLARK 8033336 CLARK FORKLIFT CONVERTER DC DC 5V MFR’S P / NO 140034 #3 13:13

The CLARK 8033336 DC-DC Converter is a vital auxiliary power supply component used in Clark electric forklifts and other material handling equipment. Its primary function is to convert the vehicle’s high DC battery voltage (from a 36V or 48V system) down to a stable, regulated 5V DC output.

This 5V power is essential for operating the forklift’s low-voltage control and sensory systems. It acts as the “power supply” for the vehicle’s electronic brain. The #3 designation differentiates it from other versions, indicating a specific output current (amperage) rating, which is higher than the #1 and #2 versions.

Key Specifications from the Label

• OEM Brand: CLARK

• Clark Part Number: 8033336

• Component Type: DC-DC CONVERTER

• Input Voltage: Designed for the nominal voltage of a 36V or 48V battery system. (The actual input range is designed to handle the fluctuating voltage of a battery under charge and discharge, typically from ~30V to 60V+).

• Output Voltage: A stable, regulated 5 Volts DC.

• Output Current: The “#3” is a key differentiator. It indicates a specific, higher amperage rating than the #1 and #2 versions. This is typically in the range of 10-15 Amps, providing substantial power for vehicles with extensive electronic features or more demanding control systems.

• Manufacturer’s Part Number: 140034 (This is the part number from the original manufacturer who produced this converter for Clark).

Key Features and Functions

• High-Current Voltage Regulation: Provides a “clean,” stable 5V supply from a variable battery voltage, which is crucial for the precise operation of multiple sensitive electronics simultaneously.

• High Current Capacity: The #3 rating means it is designed to power systems with significant electrical loads, ensuring stable voltage even when multiple systems are active.

• Electrical Isolation: Provides isolation between the high-voltage battery circuit and the low-voltage control circuit, protecting delicate components from voltage spikes and transients on the main power line.

• Protection Circuits: Includes built-in protection against:

  • Input Under-Voltage: Prevents operation if the battery voltage drops too low, protecting the battery from deep discharge.

  • Input Over-Voltage: Protects the converter from voltage spikes.

  • Output Over-Current / Short-Circuit: Protects the converter and the connected control units if a fault occurs.

  • Over-Temperature: Shuts down if internal temperatures exceed safe limits.

• System Power: Supplies power to critical systems such as:

  • The Main System Controller (the vehicle’s computer)

  • Throttle Position Sensor (Accelerator pedal)

  • Operator Presence Sensor (Seat switch)

  • Dash Display / Warning Lights

  • Solenoid Coils in the hydraulic control valve

  • Advanced attachments with their own electronic controllers

Common Applications

This specific converter (#3) is used in Clark electric forklifts that require a high-capacity 5V power supply. This is common in:

• Larger, more complex forklift models

• Vehicles with advanced dash displays or monitoring systems

• Forklifts designed to operate with electronically-controlled attachments

• Systems with multiple electronic control units

Important Notes for Replacement/Repair

1. Critical Function: This is not a motor controller. It is a low-voltage power supply. Without it, the forklift will not function.

2. Amperage Code is Critical: The #3 amperage code must be matched. Installing a lower-rated converter (e.g., #1 or #2) could cause it to overload and fail, leading to system shutdown.

3. Exact Replacement: The part number (8033336) and amperage code (#3) must be matched for a guaranteed compatible replacement.

4. Diagnosis: Failure symptoms include:

   • Complete loss of power (no dash lights, no response to key switch)

   • Intermittent operation or resets

   • Diagnostic trouble codes related to control unit communication or sensor faults.

5. Installation: This is typically a plug-and-play component, but it is essential to disconnect the main battery power before installation to prevent short circuits.