Derrick Hall ·
Every winter we see the same pattern: a fleet runs fine through autumn, the temperature drops below freezing overnight, and a third of the yard will not start in the morning.
Batteries are the obvious culprit, but they are rarely the root cause. A battery that tests fine at 60°F can lose 40% of its cranking capacity at 0°F, which turns a marginal starter draw or a parasitic drain into a no-start.
The seven checks: battery load test under load, parasitic draw measurement, starter current draw, glow plug or grid heater function, coolant freeze point, fuel filter and water separator, and block heater cord continuity.
None of these take long. All of them are far cheaper in October than in January.