Direct answer
First distinguish no-crank from an engine that cranks but will not start. For a no-crank complaint, preserve the key-action response, display messages and recent electrical work. A click or a bright display does not by itself prove the battery or starter is serviceable. A parts decision needs the appropriate electrical assessment.
Use an unambiguous complaint description
“Will not start” can describe different events. State whether the engine was observed to rotate, whether there was a click and what the display did during the original attempt. If uncertain, say “rotation not confirmed.” Record the machine and engine identity, because an excavator and haul truck can have different start-control arrangements. Do not keep repeating start attempts just to improve the description.
What to record before a service or parts decision
| Record | What to include and why |
|---|---|
| Observed response | No rotation, reported click or uncertain response; retain the original description. |
| Display record | Exact warning/message and visible response during the original event. |
| History | Recent battery, starter, wiring or accessory work, plus the date the complaint began. |
| Electrical assessment | Technician’s applicable circuit reference, test conditions, measured values and conclusion. |
| Proposed part | Exact starter or other component number, electrical/application specification and included assembly scope. |
What the observations do—and do not—establish
The technical assessment may need to consider the battery supply, connections, start command and the machine’s control/interlock requirements. Naming these areas is not an instruction to bridge a terminal or bypass a control. A static observation is not the same as a documented test under the conditions specified by the manufacturer. Keep measured evidence separate from assumptions about what a click means.
Turn the record into a clear service handoff
If a starter is recommended, attach the service finding to the inquiry and preserve the old label where safely available. Confirm the exact machine/engine application and mounting/electrical requirements through the appropriate catalog. If the engine rotates but does not run, redirect the complaint to the relevant starting/running assessment rather than continuing to treat it as no-crank.
Safe limits for this guide
Do not bridge starter terminals, bypass neutral/start interlocks, improvise battery connections or probe an energized circuit from this article. Batteries and high-current wiring require qualified handling and the specified isolation procedure.
Machine and parts context
This is a general service-planning guide. The linked machine pages organize identification information; they do not make the workflow a model-specific repair procedure.
Frequently asked questions
Does a click prove the starter has failed?
No. Preserve the observation and obtain the appropriate circuit assessment.
Is a working display proof of adequate starting supply?
No. It is an observation, not a complete battery or circuit test.
What if the engine rotates normally?
That is a crank-but-no-start complaint and needs a different diagnostic scope.
Sources and scope
- Komatsu parts and documentation access — Manufacturer route to machine-specific parts and service documentation. This portal does not supply the individual limits or application approval for this guide.
The observation checklist is Danch Machinery editorial guidance. No customer case, measured result or technician sign-off is claimed. Published or updated 14 September 2026. Obtain the current documentation for the exact machine before any technical procedure.
Request a parts identification check
Send the complete model and serial, component position, exact number or clearly marked uncertainty, quantity and available service findings. Danch Machinery supplies genuine parts; a quotation does not replace a technical diagnosis.
About this guide
Published by Danch Machinery as general parts-identification and service-planning information. It is not a signed technical inspection or a machine-specific repair approval. Refer to the sources and scope stated in the article; confirm service procedures and fitment with the current manufacturer documentation for the exact machine.
Machine configurations and service requirements can differ by model, serial number and market. Confirm procedures and fitment with the current manufacturer documentation for your exact machine.
