The following commentary does not necessarily reflect the views of AgWeb or Farm Journal Media. The opinions expressed below are the author's own.
As a farm machinery mechanic and writer, Dan brings a hands-on approach that only a pro can muster. Along with his In the Shop blog, Dan writes a column by the same name as well as the Shop Series for Farm Journal magazine. Always providing practical information, he is a master at tackling technical topics and making them easy for all of our readers to understand. He and his wife, Becky, live near Bouton, Iowa.
Back in the day when the electrical system on farm machinery consisted of a battery, the starter, a couple gauges and a few feeble lights, it was enough to ground things to the machine's frame with a little jumper wire to the base of the light or other electrical component.
That doesn't work very well on modern farm equipment. Most electronic components have a separate ground wire that eventually connects to a circuit connected directly to the battery's negative terminal, or to a specially designated grounding lug on the machine's frame.
So when testing electronic circuits, make sure you use the component's ground wire/pin rather than grounding to a nearby piece of metal. That way you'll not miss a break in the dedicated ground wire.