The proximity sensor is fitted to all Generation 3 trailers and earlier Sport Range trailers manufactured prior to SmartControl. These trailers use the sensor to detect when the deck has reached the fully raised position.

Later Sport Range trailers with SmartControl do not have a proximity sensor. SmartControl senses the rise in current to the lifting system when the trailer reaches the maximum up position or is overloaded by an overweight load. If you have a SmartControl-equipped trailer, this article does not apply to you.

The proximity sensor is a standard OMRON inductive proximity sensor — the same type used as a limit switch in pre-PLC controlled machinery such as hoists, cranes, and industrial winches. Its job is simple: detect when the lifting arm reaches the top of its travel and shut the winch off.

The system works on a basic sense-signal-stop principle:

Sense. As the deck raises, the lifting arms travel upward. The proximity sensor is mounted under the lifting arm and detects the arm when it reaches the fully raised position.

Signal. When the sensor detects the lifting arm, it sends a signal to a micro relay at the winch solenoid. The small amber indicator light on the sensor turns off, confirming the sensor has triggered.

Stop. The micro relay cuts power to the main winch solenoid, and the winch stops.

If the proximity sensor fails, it cannot detect the lifting arm at the top of its travel. The micro relay never receives the signal to cut power, so the winch continues running after all four lifting arms have landed on the latch plate. The winch strains under load as it attempts to pull the rope or cable system apart — this will overload the winch and can damage the winch rope and winch.

• Clicking noise from the winch during raising (winch cycling on/off)

• Small amber light on the sensor stays on when the deck is fully raised

• The winch does not stop running when the deck is fully raised — all four lifting arms have landed on the latch plate and the winch continues to run, straining under load

• Intermittent raising — sometimes stops correctly, sometimes doesn't

Type: PNP (Normally Open)

Measurement: 420mm tip-to-tip

Location: Under the lifting arm

Part Number: WA-OMRON-00

1. Raise the trailer deck fully using the remote.

2. Check the small amber indicator light on the sensor. If it stays on when fully raised, the sensor is likely faulty or out of adjustment.

3. Inspect the sensor face. Look closely at the magnetic tip of the sensor for chips or damage. Small stones can get between the lifting arm and the sensor during use — if the sensor face is chipped or damaged in any way, the sensor will not work and must be replaced.

4. Check the sensor position. If the sensor face is undamaged but the amber light stays on when the deck is fully raised, the sensor may have moved and is no longer close enough to the lifting arm to detect it. Adjust the sensor closer to the lifting arm. If the lifting arm is physically hitting the sensor, the sensor is adjusted too high and too close — the impact will damage the magnetic tip and the sensor will need to be replaced.

5. If the sensor face is undamaged and the position is correct but the sensor still does not trigger, replace the sensor.

1. Disconnect the trailer battery.

2. Remove the faulty sensor from under the lifting arm (note the orientation and mounting depth).

3. Install the new WA-OMRON-00 sensor loosely in position — do not tighten the lock nut yet.

4. Reconnect the wiring harness.

5. Reconnect the battery.

6. Set the sensor position. Raise the trailer fully using the remote. The winch will begin to load up when the trailer is fully raised — at that precise moment, release the up button. With the deck fully raised and the lifting arm in its final position, adjust the sensor upward toward the lifting arm until the small amber light on the sensor turns off. The sensor must be close enough to detect the arm but must not touch it.

7. Lock the sensor in position with the lock nut.

8. Test by lowering and raising the deck. Confirm the winch stops automatically when the deck is fully raised and the amber light turns off.