Caterpillar 336E Excavator Wiring Harness — All 7 Sections
The Caterpillar 336E uses 7 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 |
| Engine Harness | Intermittent misfire or a dead cylinder | Engine Harness group |
| Injector Harness | One cylinder cold or dead | Injector Harness group |
| Sensor Harness | Several sensor codes at the same time | Sensor Harness group |
| Valve Control Harness | One function slow or dead, others normal | Valve Control Harness group |
External Harness 2 parts
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 |
|---|---|---|---|
| 377-8095 | External Wiring Harness | $3150.00 | In stock |
| 421-7588 | External Wiring Harness | $3150.00 | 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 |
|---|---|---|---|
| 361-2497 | Engine Wiring Harness | $1098.90 | 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 |
|---|---|---|---|
| 637-2653 | Fuel Injector Wiring Harness | $203.50 | In stock |
Sensor Harness 1 part
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.
| Part # | Description | Price | Stock |
|---|---|---|---|
| 327-9949 | Hydraulic Oil Temperature Sensor Wiring Harness | $200.00 | In stock |
Valve Control Harness 2 parts
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 |
|---|---|---|---|
| 369-0155 | Control Valve Wiring Harness | $339.90 | In stock |
| 369-0168 | Boom Telescopic Valve Wiring Harness | $119.90 | In stock |
Not sure which of the 7 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.