Caterpillar 320D Wiring Harness — All 5 Sections
The Caterpillar 320D uses 5 separate harness sections that ECS builds. They are not interchangeable: the part number on your old loom decides which one you need. Below they are grouped by where each section sits on the machine, with the part numbers and the symptoms that point to each group.
Which section do I actually need?
Start from the fault, not from the part name. Find the symptom the operator reports, then open that group.
| Section | First symptom to look for | Group |
|---|---|---|
| Fuse Box Harness | The same fuse blows repeatedly | Fuse Box Harness group |
| Engine Harness | Intermittent misfire or a dead cylinder | Engine Harness group |
| Injector Harness | One cylinder cold or dead | Injector Harness group |
| Pump Control Harness | Power derate with no hydraulic leak | Pump Control Harness group |
Fuse Box Harness 1 part
It sits in or immediately behind the fuse and relay box, where battery power is split into the individual circuits.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 259-5223 | Fuse Box Wiring Harness | $595.00 | In stock |
Engine Harness 1 part
It runs inside the engine compartment, clipped along the block and head and routed past the front cover. On most machines it is the longest harness on the engine side and the one closest to exhaust heat.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 296-4617 | Engine Wiring Harness | $149.00 | In stock |
Injector Harness 1 part
It sits under the valve cover on most engines, passing through the gasket or the head into the injector bores. It is the hottest electrical component on the machine.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 305-4893 | Injector Wiring Harness | $54.00 | In stock |
Pump Control Harness 1 part
It runs in the pump compartment between the pump controls and the machine harness.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 275-6803 | Fan Pump Wiring | $149.00 | In stock |
Wiring Harness 1 part
| Part # | Description | Price | Stock |
|---|---|---|---|
| 579-4200 | Wiring Harness | $65.00 | In stock |
Not sure which of the 5 sections is yours?
Send a photo of the tag on your old harness to WhatsApp +86-13714733803 and we will confirm the part number against this list before you order. Getting the section wrong is the most common reason a replacement does not fit.