A logistics center reported that a Linde E20 electric counterbalance forklift would hesitate (delay) for 2 seconds before moving when the accelerator pedal was pressed. Occasionally, the machine would stop completely while driving.
The technician checked the battery voltage, which was 48V (normal). He then checked the "Battery Connector" (the large plug connecting the battery to the truck). He found that the pins on the truck-side connector were blackened and corroded due to arc flashes. This corrosion created a high resistance point. When the accelerator was pressed, the high current flow caused a voltage drop across the connector (dropping to 40V). The controller sensed this low voltage and triggered a "Under-Voltage Protection," causing the hesitation.
However, the intermittent stopping issue was traced to the "Brake Pedal Switch." Linde forklifts have a safety interlock: if the brake pedal is pressed slightly, the drive motor cuts power. The technician found that the plastic actuator pin on the brake pedal linkage was worn. When the driver drove over a bump, the pedal would vibrate and press the switch momentarily, cutting power. The worn connector pins exacerbated this by causing voltage fluctuations.
The repair involved replacing the battery connector contacts (using high-quality copper pins) and cleaning the battery terminals. The brake pedal switch linkage was adjusted to ensure it only activated when the pedal was pressed 5mm. The controller's fault memory was cleared. The forklift accelerated smoothly and ran without interruption.
