Fault Phenomenon: Barrett electric tow tractor while driving, the tow pin suddenly detaches, separating the tractor from the trailer.

Troubleshooting Process:
– Checked tow pin lock: lock not secured.
– Checked spring: spring broken.
– Checked wear: pin hole excessively worn.
– Checked operation: improper operation.

Root Cause: The tow pin lock spring broke, causing automatic detachment.

Required Parts: Tow pin lock assembly.