Not Making the Grade

With the advanced electronic components and increased amount of in-cab gadgets in big rigs these days, knowing the ins and outs of modern electrical systems is more important than ever for fleet technicians. Yet, some startling statistics bear out that this often-misunderstood system is not getting the attention it deserves and is subsequently eating away at many a company’s profits.

As the long-time Vice-chairman of Technology & Maintenance Council (TMC) electrical study group and president of the Rogers, AK-based Purkey’s Electrical Consulting, Bruce Purkey works with the biggest fleets in the nation--J.B. Hunt, Fed-Ex, Rider, Penske--where he sees some startling, across-the-board ignorance about electrical systems.

And it’s not just the big guys.

Purkey says the average score in a recent TMC electrical systems test was a paltry 37.6 percent; far from a passing grade. But he’s not just sitting in his office crunching numbers and wringing his hands about poor technicians--he is out in the field trying to prevent more of the horror stories he has experienced first-hand.


Recently, Purkey was training technicians from a major truck leasing company who just bought $5,000 worth of electrical system parts to try to repair a truck that wouldn’t start. The problem? Someone left off a ground cable from the starter to the engine block, but no one realized it until Purkey pointed it out.

“Instead of going through the normal path back to ground, (electricity) was going down the frame, up a cross-member, through the drive shaft and all the way back, generating about a two-and-a-half volt drop,” he says. “So (the technician thought) ‘Even though my alternator was perfect, could I ever get the right voltage of batteries? No. Were they always discharged? Yes. Did it cause me to burn up starters? Yes.’ And when the guy went to test it and he saw the alternator voltage was real low, he thought (to change the alternator). It was just a round-robin circle of replacing components, and it was a 35-cent fix.

“That happens all the time.”

Purkey helped put together TMC’s guidelines on voltage drops back in 1984 and is now in the process of re-writing it for modern applications. He says one thing has not changed throughout the years: Working in sequence is absolutely critical to accurately diagnose charging problems.

“First you’ve got to make sure your batteries are in a good state of charge,” he says. “The second thing is, do voltage drop checks on that charging cable. For years technicians checked the batteries maybe and the alternator but forgot about the cables. If my alternator has a setting of 14 and I’ve got a two-volt drop in my cables, do I get 14 volts in the battery? Hell, no. So can the batteries be charged, especially in cold weather? Hell, no. So I’ve got discharged batteries that cause me to have cranking problems, so everybody works on the wrong side of the circuit when it was just the cables that were bad. When it comes to electric systems, everybody does what they want to do, because you can’t see it.”

Travis Hopkey of the Santa Fe, CA-based Phillips Industries says a recent eye-opening trip to a major fleet garage made it all too clear how little some technicians know about simple wiring, much less complex electrical systems.

“One of the battery cables had shrink-tubing over it but they didn’t heat it to shrink it down, so you could just slide it up and down the cable,” Hopkey says. “You can imagine running down the road with the magnesium and calcium chloride that will just eventually eat (the cables) away, and (the rest of the technicians) will be scratching their heads later, saying ‘Well, what happened?’ People aren’t trained properly, or the training is inadequate.”


Careless techs have probably helped gain a sale or two for AIM, the Rancho Cordova, CA-based manufacturer of remanufactured starters and alternators for the heavy duty aftermarket. President Steve Seabourne says many electric system problems he sees are simply a result of under-diagnoses stemming from a lack of knowledge.

“They’re using the alternator or starter to troubleshoot an electrical issue without really doing some proper tests,” he says. “The light comes on so they replace the alternator without really checking anything out… then the car ends up coming back in and they have to redo the job and maybe they might just say, ‘Hey, this is a bad alternator, send me another one,’ and after a few times they finally say ‘Well, I better check something else out.’”

Eric Karr, account manager with Mitsubishi Electric Automotive America, says preparation and knowledge goes a long way in mastering electrical systems, and getting back to the basics is the starting point.

“You have to think critically,” he says. “In our training guide, we devote several pages at the beginning to the fundamentals of electricity—Ohm’s Law, a series of parallel circuits, what is the effect of current on different things—things you have to have some knowledge about. There is more knowledge out there, you just have to go and find it.”

Failure to grasp the basics of electrical systems can end up costing a fleet big-time, Karr says—and it happens far too frequently.

“We’ve had several occurrences where we get two or three parts back from the same vehicle and occasionally you’ll get a guy who says, ‘Gosh darn it, the starter just isn’t working correctly! I’ve had three of these things fail in my truck—what’s going on here?’” Karr says. “And a lot of times when a component fails multiple times on one vehicle, it’s not always the component itself that’s the culprit, it’s the system—it can be other parts in the system that’s causing that to fail.”


It is up to the technicians to stop simple errors from turning into costly fixes, but many times they fail to diagnose the real problem. One of the reasons many techs are deficient with electrical systems is because they came from a mechanical background, says C. E. Niehoff engineer James Becker. Modern electrics in trucks can simply be overwhelming for some, he says, and the result is often a knee-jerk reaction or guesswork instead of a measured, professional evaluation.

“If there’s a problem, they’re just going to replace (a part) and see if it works,” he says.

Becker says the way to get better efficiency from electrical systems is simply better training for those who maintain them.

“You’ve got to learn how to use the voltmeter, you’ve got to figure out if the problem is from the regulator or the alternator, or if it’s a battery problem,” Becker says. “If the battery is highly discharged, it’s going to load down the electrical system… and you’re going to think, ‘Oh, I’ve got low voltage—I’ve got a bad alternator.’ And it may have nothing to do with the alternator. There’s more electronics and the alternators have gotten bigger and the loads have gotten higher, so there’s more stress on a system.”

Proper troubleshooting is the only way to identify the source of a problem without replacing half the vehicle in the process, Seabourne says.

“We actually have come out with a checklist (because) a lot of these guys have been in the business and they think they know everything,” Seabourne says. “You hand them something like that and they are insulted by it, but often those are the guys not doing it right. And there are other guys that want to learn and are open to better ways of doing their system analysis. There are classes, training offered out there and (technicians) should be open to that.”


The real trick in training your techs is convincing them this new knowledge will help them in the long run, says Corey Glassman, President of the Automotive Training Managers’ Council and Automotive Program manager for Fluke, the Everett, WA-based electric test tool manufacturer.

“(Trainers) will tell you even through they spend a lot of money and time putting together a great program, one of the challenges is getting the butts in the seat,” Glassman says. “You can do on-line training, but after you’ve worked a long, hard day, the last thing on your mind is to go home and be trained. And if they are a working technician in a shop, the last thing the shop wants do to is take them out of their current environment where they’re making (the shop) money and getting vehicles fixed, and put them into training.”

So how do you convince a know-it-all technician that they, too, could use some updated electric training? Glassman says it is all how you word it.

“If you call it advanced-level training, they’re more apt to come to the training and listen,” he says. “They don’t want to sit with their peers and raise their hand and show they’re deficient in some fashion. A lot of technicians don’t know what they don’t know.”

Training alone is not enough, though—Purkey says the true test is retention.

“You can train a guy, but if he doesn’t get to use and apply it, he can sure lose those skills very quickly,” he says. “One of the things every fleet manager in America should start doing is, when you buy the equipment guys need, make sure they use it. (Otherwise you get) ‘I just spent $1,000 for a piece of equipment and you’re gonna use a $1.98 test light that could blow circuits?’ And yet you watch, and they do it all the time.”