"The battery cable should be something you look at when you have a charging system problem and they can do it with a glance," he says. "A bad cable will cause a domino effect with the batteries, starter and alternator, and this is designed to give them a quick check before they do any other maintenance, because changing out a starter or alternator is hundreds of dollars of work. It's not just the cost of the parts, it's the downtime and the labor—if you see you've got a bad cable, that's a quick $25-$50 fix and the guy's back on the road."
While doing basic checks should be a starting point for any tech trying to diagnose an electrical problem, some new technology is also helping keep trucks on the road, and shop costs down. Corey Glassman, President of the Automotive Training Managers' Council and Automotive Program manager for the Everett, WA-based electronic test tool and software manufacturer Fluke Corporation, says new electronic devices like digital multi meters and voltmeters are becoming necessary tools for fleet technicians because electrical problems can often take some digging to find.
"You may have bad, crimped connections or poorly soldered connections, or perhaps (degraded) cables from flexing over time, because the diesels shake quite a lot," Glassman says. "That shaking it loosens connections or perhaps flexes cables where from the outside the cable might look OK, but internally, it may have a bunch of broken conductors and so that increases resistance. You can't tell just from looking at it."
When it comes to modern electronic equipment in a busy shop, Glassman says accuracy and durability are crucial.
"Our products are built for a rugged environment," he says. "If test leads, for instance, get caught in a fan belt or around a fan… we've had calls from customers that says the last thing they saw was the meter flinging across the shop and hit the concrete wall on the other side but it was still working. Repeatability and accuracy (are) important when you're trying to make numerous measurements because when you hook up to the circuit, if all other conditions are the same, your meter should continue to read the same values."
With the recent increase of in-truck electronics, there is more to maintaining these basic but critical electronic systems than ever before. How are technicians around the country keeping up with the changing technology?
In fact, they seem to be failing miserably—Purkey says in a recent TMC electric systems test, the average technician's score was a meager 37.6 percent.
How much do your techs know about electrical systems? Are they spending thousands of your dollars on what could be a 50-cent fix? Or worse?
Our October Heavy Duty story will further explore this misunderstood system, and experts will share horror stories about the sizeable knowledge and training gap that seems to be widening for many technicians.