Rodent damage, and why it happens to the machine that stands still

It is not bad luck, it is not random, and it is not a problem that happens to careless people. A machine that stands still for nine months in a dry building is, from a mouse's point of view, a heated shelter full of bedding material with nobody in it.

Why the wiring specifically

Three things come together. Insulation is soft, chewable and exactly the right size to shred for a nest. A loom is a warm, enclosed, protected run — the safest corridor in the building. And rodents gnaw constantly because their teeth do not stop growing, so they are not eating the cable, they are wearing their teeth down on it.

There is a fourth factor that is more recent and it is worth knowing about: a good deal of modern wire insulation is made with plant-derived plasticisers rather than the older petroleum ones. Whether that makes it actively attractive is argued about, and it certainly does not make it less so. Either way the practical consequence is the same, and it is worse in machinery that stands than in machinery that moves.

Why the damage is never one wire

Because it is a nest, not a bite. By the time anybody notices, the animal has been living in the loom for weeks and has taken insulation from wherever it was convenient across a length of it. The count is not knowable until the loom is opened along its run, which is why an estimate before that is described as a guess — and why this is the one job on the rate card with an hour range wide enough to look alarming.

It is also why the damage is not always where the symptom is. Conductors shorted together inside a bundle produce faults on circuits that have nothing to do with each other, and a machine that suddenly has six unrelated warnings is usually one nest rather than six faults.

What to do in the autumn, which costs almost nothing

• Clear the grain, chaff and straw out of the machine before it is parked. That is the food, and without the food the shelter is much less interesting.
• Leave the cab and any engine covers open rather than closed. Enclosed dark spaces are the attraction; an open machine is a worse house.
• Do not park it against a wall of stored straw or feed. What is next to the machine matters more than what is in it.
• Start it and move it every few weeks over the winter. Machinery in use is machinery nothing nests in, and it does the batteries good as well.
• Look, in January. Nesting material in a loom run, droppings on a step or shredded insulation under a machine is a cheap repair now and a lost day in August.

Why it should be found in February

The arithmetic is not close. Rodent damage found in the quiet season is a morning's work, done properly, with the loom opened and every conductor identified and repaired. The same damage found on the second day of harvest is an evening callout at the after-hours rate, a repair done under a light in a field, and a machine standing still while the weather turns.

That is most of the argument for the pre-season check, and it is the single most useful thing this workshop sells.

What this article cannot tell you

How much of it there is in your machine. Nobody knows that until the loom is opened, including us, and any number given before that hour is a guess described as one.

Nothing on this website names a fault on your vehicle. Not the intake, not the articles and not the telephone. A fault named from a description is a guess, and the whole argument for this trade is that a measurement is not a guess.