Caterpillar 320C Wiring Harness — All 3 Sections
The Caterpillar 320C uses 3 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 |
|---|---|---|
| External Harness | Several circuits dead after rain or a wash | External Harness group |
| Internal Harness | Interior functions dead while the machine runs | Internal Harness group |
| Instrument & Interior Harness | One instrument or accessory dead | Instrument & Interior Harness group |
External Harness 1 part
It is the outside harness on the machine body — exposed to rain, wash-down, mud and UV. On most machines it is the section most often replaced.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 256-4013 | External Wiring Harness | $1042.00 | In stock |
Internal Harness 1 part
It runs inside the cab or inside a compartment, behind trim and panels, away from weather but exposed to chafing and to heat from nearby components.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 198-0857 | Internal Wiring Harness | $268.00 | In stock |
Instrument & Interior Harness 1 part
It sits inside the cab, behind the trim, feeding the instruments and controls the operator sees and touches.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 244-8554 | Cab Floor Wiring Harness | $893.00 | In stock |
Not sure which of the 3 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.