Caterpillar 374D Wiring Harness — All 5 Sections
The Caterpillar 374D 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 |
| Instrument & Interior Harness | One instrument or accessory dead | Instrument & Interior Harness group |
| Valve Control Harness | One function slow or dead, others normal | Valve Control Harness group |
| Breaker / Hammer Harness | Breaker will not fire, carrier runs fine | Breaker / Hammer 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 |
|---|---|---|---|
| 342-2890 | Fuse Box Wiring Harness Assembly | $536.00 | 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 |
|---|---|---|---|
| 354-0049 | Engine Wiring Harness | $238.00 | 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 |
|---|---|---|---|
| 342-2886 | Cab Interior Wiring Harness | $1042.00 | In stock |
Valve Control Harness 1 part
It runs from the control valve block on the frame up to the ECM or the machine controller, clipped along the boom or the frame as it goes.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 350-8198 | Solenoid Valve Wiring Harness | $357.00 | In stock |
Breaker / Hammer Harness 1 part
It runs from the breaker or hammer circuit on the boom to the control box in the cab, and takes more flexing than any other section on the machine.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 342-2892 | Breaker Wiring Harness | $744.00 | 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.