The Ram Completed Its Travel, but the Motor Never Received a Stop Command
The upper limit had already been replaced. The motor stopped only when the selector moved to Off, while pressing the lower pedal also changed the behavior.
The exact sequence
- The ram moved down normally.
- It reversed at the bottom and returned upward.
- At the top, the motor continued to run.
- Moving the selector to Off stopped it.
- A new upper limit switch had not changed the complaint.
- Pressing the lower pedal could stop the mechanism.
The same symptom can have a different cause. The sequence points to a control or interlock path, but it does not prove a particular switch without testing.
Why the switch path became more important than the motor
The discussion described a switch-controlled mechanism and proposed the drawer switch plus the momentary switch at the lower pedal or actuator. On the diagram shown in this case, the latter was position 14. A shorted or mechanically stuck momentary contact could keep the command active.
Technicians also kept plastic gears and the motor path available, but considered the motor less likely from experience. No component was proved or replaced successfully in the source.
What to capture before another service visit
- Provide the complete model and serial number.
- Record a full down-and-up cycle from a safe distance.
- Note exactly which control or drawer movement stops the motor.
- Preserve the old and replacement upper-limit part numbers.