SPM-HEP-5039 is the short fuel injector harness with a grey angled four pin connector and four ring terminal leads in red, orange, yellow and brown to the injector solenoids. It is used on Komatsu PC300-8 and PC350-8 excavators. This aftermarket version has the same mounting and electrical connector as the original, so it plugs in and bolts on where the old one came off.
It replaces Komatsu 6745-81-9240 and Cummins 3968886.
Sold as one unit. Check the number on your old part, or in the parts manual for your machine, before ordering.
Technical properties & sizes
Specifications
| Part Type |
Injector Wiring Harness |
| Replaces |
Komatsu 6745-81-9240 |
| Machine |
Komatsu PC300-8, PC300LC-8, PC350-8, PC350LC-8 excavators |
| Engine |
Komatsu SAA6D114E-3, Cummins 6CT |
| Cross references |
Cummins 3968886 |
| Fits |
Komatsu PC300-8, PC300LC-8, PC350-8 and PC350LC-8 excavators (SAA6D114E-3 engine) and Cummins 6CT engines |
| Condition |
New, aftermarket |
| Stat. HS-Code |
854430 |
| Country of Manufacture |
China |
Compatibility
Komatsu machines
Komatsu PC300-8, PC300LC-8, PC350-8 and PC350LC-8 excavators (SAA6D114E-3 engine) and Cummins 6CT engines
Check the part number on your old unit before ordering.
Part numbers
| Komatsu Part No.(SPM Part No.)
|
Fits |
|
6745-81-9240(SPM-HEP-5039)
|
Komatsu PC300-8, PC300LC-8, PC350-8 and PC350LC-8 excavators (SAA6D114E-3 engine) and Cummins 6CT engines |
|
3968886(SPM-HEP-5039)
|
Komatsu PC300-8, PC300LC-8, PC350-8 and PC350LC-8 excavators (SAA6D114E-3 engine) and Cummins 6CT engines |
Applications & use cases
Intermittent faults and warning codes
Chafed, crushed or corroded wires in an engine or main harness give faults that come and go: sensor codes, a rough running engine or a machine that will not start. When several sensors fault at once, look at the harness.
Heat and rodent damage
Harnesses next to the exhaust and turbo go brittle and crack, and rodents chew the insulation on machines that stand. A new harness is quicker than repairing many wires.
Burnt or corroded plugs
Green corrosion or melted pins in the plugs cause high resistance and false readings. Replacing the harness renews every plug at once.
Fitting tips
Disconnect the batteries first, photograph or label every plug before removing the old harness, route the new one along the same clips and away from hot and moving parts, then clear the fault codes and test.
Price beat guarantee
We check what other aftermarket sellers charge for this same part. Their prices on the date we checked:
| Seller |
Price |
Checked |
| SINOCMP |
USD 149.00 |
2 Nov 2026 |
| eBay, aftermarket seller |
USD 152.87 |
2 Nov 2026 |
| FridayParts |
USD 182.60 |
2 Nov 2026 |
| Spare Part Mart |
USD 84.00 |
Today |
Our price of USD 84.00 is 44% to 54% less than these sellers.
Found this part cheaper somewhere else? Send us the listing and we will beat it by 5% under our Price Beat Guarantee. Every order is also covered by our 30 day money back guarantee.
Frequently asked questions
Will it fit my Komatsu PC300-8?
Yes, it was made for the Komatsu PC300-8, and 4 more listed under compatible equipment. Check the old wiring harness is marked 6745-81-9240 or one of the cross references, because makers change parts between serial ranges.
How often should I replace the wiring harness on my Komatsu PC300-8?
On the Komatsu PC300-8, there is no fixed interval. It is changed when it fails, and many fail from water in the plug or chafed wiring rather than wear.
What are the signs the wiring harness needs replacing?
A fault code for this circuit, readings that jump or stay fixed, or a part that does not respond with power at the plug.
Should I grease the connector?
A little dielectric grease keeps water out of the plug on machines that work outside. Make sure the terminals are clean and tight first.
Do the fault codes need clearing?
Usually. Clear them after fitting and run the machine, so old codes are not mistaken for a new fault.
Is this a genuine Komatsu 6745-81-9240?
No. It is an aftermarket wiring harness made to replace the Komatsu 6745-81-9240. It is not made by the original manufacturer; the number only shows what it replaces.