Komatsu D275A-5R Engine Sensor Wiring Harness
Engine Sensor Wiring Harness for Komatsu D275A-5R, OEM Quality Replacement Part #6261-81-8120
Fitment
Fits the Komatsu D275A-5R. This is the only section ECS currently lists for this machine, so confirm the part number on your old harness against 6261-81-8120 before ordering.
Part number reference for the 6261-81-8120
This harness is one part sold under one number. Suppliers and parts books write it differently — you may see it as 6261-81-8120, 6261818120. They are all the same part; the number on the tag of your old harness is what settles the order.
If the tag shows a different number entirely, do not order by eye — send us a photo of it on WhatsApp and we will match it against the catalogue before anything ships.
Where this harness sits on the Komatsu D275A-5R
It is the branch that carries pressure, temperature and speed signals from sensors back to the ECM. It usually runs low along the frame or the engine, wherever the sensors are.
What it connects
- Sensor group to the ECM — analog and digital inputs — pressure, temperature, speed, position.
- ECM to sensor supply and ground — a shared 5 V reference and return, which is why one bad branch can pull several readings down together.
What a failing Komatsu D275A-5R harness looks like
| What the operator reports | Why the harness fits that symptom |
|---|---|
| Several sensor codes at the same time | Shared reference or ground in the harness, not several failed sensors. |
| Readings that jump when the machine shakes | A signal wire making and breaking contact. |
| Implausible values at cold start | A reference voltage that is being dragged down by a short. |
| Codes that clear after a restart | Intermittent — the circuit, not the sensor. |
These are circuit-level symptoms, not a diagnosis. The same behaviour can come from a sensor, an ECM input or a mechanical fault — the checks below are how you tell them apart.
How to confirm it is the harness before you buy
- Compare the part number on the old harness. The number is printed on a tag or moulded into the main connector body. If it does not match, stop — stop here and send us a photo, because two sections of the same machine are not interchangeable.
- Resistance test the suspect run. Disconnect both ends and measure end to end. A reading that is far above the others in the same loom means broken strands; a reading to ground means chafing.
- Wiggle test under load. Back-probe the circuit with the machine running and flex the loom by hand along its length, especially at clips and at the cab or boom entry. If the meter or the fault jumps, you have found the run.
Same type of harness on other machines
- 490-6963 — Caterpillar 320GC Sensor Wiring Harness
- 135-6088 — Caterpillar 330B Engine Water Temperature Sensor Wiring Harness
- 327-9949 — Caterpillar 336E Hydraulic Oil Temperature Sensor Wiring Harness
- 552-4651 — Caterpillar 336GC Sensor Wiring Harness
- 251-0521 — Caterpillar 365C Sensor Air Filter Wiring Harness
Product Description
High-quality engine sensor wiring harness designed for Komatsu D275A-5R. This is a complete replacement harness that matches OEM specifications (Part #6261-81-8120). All connectors and wiring are tested before shipping. Direct fit installation, no modification required. Made with durable copper wires and heat-resistant insulation for long service life in heavy-duty applications. Factory direct pricing with quality guarantee.
Why Choose ECS System Parts?
- Factory Direct: we build the loom — no middlemen
- In Stock Ready to Ship: most orders leave within 24 hours
- OEM Quality: made to the original drawing, connector for connector
- 1 Year Warranty: full coverage against defects
- Worldwide Shipping: DHL, FedEx, UPS, EMS
- Expert Support: WhatsApp +86-13714733803 — send us a photo of your old harness and we will confirm the section
Technical Specifications
| OEM Part Number | 6261-81-8120 |
|---|---|
| Compatible Model | Komatsu D275A-5R |
| Harness Type | Engine Sensor Wiring Harness |
| Warranty | 12 Months |
Shipping Information
- DHL / FedEx / UPS / EMS worldwide
- Ships within 24 hours
- 3-7 days express, 7-15 days standard
- Tracking number provided
Return Policy
- 30-day return window
- Must be unused, original packaging
- Contact via WhatsApp for RMA authorization