Caterpillar 345B Excavator Wiring Harness — All 12 Sections
The Caterpillar 345B uses 12 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 |
| 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 |
| Console Harness | Console buttons dead, machine still runs | Console Harness group |
| Instrument & Interior Harness | One instrument or accessory dead | Instrument & Interior Harness group |
| Power Distribution Harness | Voltage at the battery but not at the load | Power Distribution 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 |
|---|---|---|---|
| 128-3774 | External Wiring Harness | $1428.90 | In stock |
Fuse Box Harness 2 parts
It sits in or immediately behind the fuse and relay box, where battery power is split into the individual circuits.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 155-2490 | Fuse Box Wiring Harness Assembly | $396.00 | In stock |
| 218-4697 | Fuse Box Wiring Harness Assembly | $350.00 | In stock |
Engine Harness 2 parts
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 |
|---|---|---|---|
| 117-2763 | Engine Wiring Harness | $268.00 | In stock |
| 145-0176 | Engine Wiring Harness | $291.50 | 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 |
|---|---|---|---|
| 117-2760 | Injector Wiring Harness | $149.00 | In stock |
Console Harness 3 parts
It runs from the console or the armrest switch pod into the main cab loom.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 141-9161 | Right Console Wiring Harness | $250.00 | In stock |
| 143-2826 | Console Wiring Harness | $253.00 | In stock |
| 167-3535 | Right Console Wiring Harness | $250.00 | In stock |
Instrument & Interior Harness 2 parts
It sits inside the cab, behind the trim, feeding the instruments and controls the operator sees and touches.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 141-8659 | Interior Wiring Harness | $2000.00 | In stock |
| 156-6125 | Interior Wiring Harness | $1479.50 | In stock |
Power Distribution Harness 1 part
It is a power distribution section: it carries battery positive or ground from one point on the machine to another, rather than signals.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 143-9058 | Engine Power Wiring Harness | $548.90 | In stock |
Not sure which of the 12 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.