On the 2003-2006 T1N Sprinter rear wheel speed sensor, the sensor normally has a molded sensor end that goes into the rear axle/hub area, and the other end should connect into the vehicle wiring harness with the correct connector/pigtail under the van.
If the sensor you have has two bare wires on the harness end, then one of two things is likely happening:
- The connector/pigtail is missing or was cut off, or
- The sensor is supplied as a universal/repair-style sensor that must be spliced into the existing harness.
The two wires are the speed sensor signal wires. They normally connect to the two matching wires in the factory rear ABS/wheel speed sensor harness. Ideally, you want to use the correct factory connector or repair pigtail so the sensor can plug into the van’s harness properly.
If the connector is missing and the sensor must be spliced, the connection should be made with a proper automotive weatherproof repair method:
- Match the two sensor wires to the two wires from the original harness/connector.
- Use solder and adhesive-lined heat shrink, or high-quality sealed butt connectors.
- Do not just twist the wires together or use household wire nuts.
- Keep the repair sealed from water, road salt, and dirt.
- Route the wiring the same way as original so it cannot rub on the tire, suspension, axle, or brake parts.
- After repair, clear the ABS codes and verify live wheel speed data with a scanner.
On many two-wire wheel speed sensors, polarity may not be as obvious as a normal power/ground circuit, but it is still best to keep the wire orientation the same as the original sensor if possible. If the old connector is still available, use that as your reference.
If your van-side connector is still intact, the best repair is to use the correct sensor with the correct plug. If the van-side connector is damaged or missing, then a proper repair pigtail or sealed splice repair is needed.
Please send a photo of:
- The sensor you have, especially the bare wire end
- The wiring harness under the van where it is supposed to connect
- The old sensor/connector if you still have it
With those photos, I can help identify whether you need a connector pigtail, a different sensor, or a splice repair.