Charged Up

It’s an elementary law of market economics that automakers constantly redesign their vehicles for better fuel economy, higher engine efficiency, and reduced emissions in an effort to stay ahead of their competitors. New vehicle introductions fitted with the latest technology improvements inevitably require engineers to invent new parts in order for the systems inside the vehicle to function efficiently. This is an evolving process, and over the years aftermarket manufacturers have had to constantly adapt in order to stay current. By taking a more active approach, jobbers can better predict what to expect from their technician customers when it comes to starting and charging systems failures.

Over the years, both systems have undergone significant changes in the way each is manufactured and how they operate. In the early ’80s, for example, internal regulators were added to alternators (either bolted at the back of the unit or inside the alternator itself) to control output voltage. Now they exist in 98% of alternators on the road, albeit in smaller and more efficient guises.

No more than a decade ago, conventional alternators had both the fan and the pulley on the outside of the unit. While the pulley still remains outside of the alternator, there are two internal fans (or the “birdcage,” as it is sometimes called) fitted inside the unit to reduce noise and offer more efficient cooling.

In today’s starting and charging systems, we’re seeing a trend in weight reduction for the purpose of making both lighter but more efficient.

One of the more significant developments is the use of an alternator clutch pulley in place of the fixed, locked pulley traditionally seen in older vehicles. With OEMs’ constant demands to find ways to become more energy-efficient, power systems play a significant role.

“Alternators have recently gone to utilizing a clutch pulley rather than a fixed, locked pulley for a number of reasons,” says Jim Weis, sales manager for NSA Corporation. “One of the reasons is the outputs of the alternator have gotten higher, and as a result they’re putting a heavier load on the belt and the pulley, so when that load gets dumped all at once it can cause a problem.

“The other thing is I think there are [some issues] with fuel economy–not so much the efficiency of the alternator as fuel economy advantages. In addition to being much quieter than the traditional lock-pulley, I’ve heard that the [reduction in] vibrations that occur along the belt and tensioner are pretty significant as well.” While vehicles in Europe have used this approach for several years, we’re only beginning to see them in Canada and the U.S., from manufacturers such as Chrysler, for example. However, some argue that the clutch pulley does more harm than good for alternators when it comes to longevity, and in some cases can cause the alternator to fail outright.

“Just looking at the cores that come back, [the clutch pulley] is the only thing that’s failed a lot of the time. They’re just not lasting,” says Trevor Buss, quality control manager for Dixie Electric. “It’s been going on as time progresses. The rollers in some clutches were wearing out after a short period of time.”

It’s not just the way alternators are designed that’s changed, but also how the charger interacts with the vehicle’s computer while in operation.

“Alternator regulators are interfacing more with the car’s computer, and some of them have features which can lower the charging voltage,” notes Buss. In such cases the ECU tells the alternator to only charge at 80%, if it finds that it would be unnecessary or wasteful to charge at full capacity.

“You have an economy mode that only goes to that level, dropping the battery voltage a little bit, essentially telling it that it does not want to provide 100% charge to a battery and finds that it would be unnecessary and wasteful,” says Mohammad Samii, owner of Sammy’s Auto Electric Service and technical coordinator of APRA’s electrical training.

In starting technology, while we’re also seeing a trend in weight reduction and efficiency, we’re also seeing a shift in the way starting motors are designed, as Samii explains:

“The older starters had a round field. There was a coil that generated the magnetic field and made the armature turn. Those round fields are gone and now [there are] pieces of permanent magnets inside which create the magnetic field. So the starters are much wider, more efficient, and probably a lot easier to manufacture. On the starter side, it’s a matter of weight reduction and perhaps (while we don’t see it in all), a smaller battery, which combined allows for some savings in weight.”

“In the last fifteen years, [starters] went to what is called a gear-reduction starter. It is much smaller and is able to put out the same torque as a much [older model] because it uses a kind of transmission inside,” says Joe Rinaldi, president of Armatures DNS2000. “Basically what’s happening is they’re spinning the starter faster. It’s lighter and is able to start with less power, for example if there’s less power in the battery. It eliminates the hot-soak situation where some cars would normally burn hot if engines are at idle.”

One of the challenges for jobbers working in the aftermarket has been getting information from the OEs, especially when it comes to problems with starting and charging systems. Aftermarket manufacturers, technicians, and counterpeople alike consult various sources in order to get the appropriate information when it comes to electrical faults.

“There’s a lot of miscommunication between the OE and the aftermarket, leaving everybody in the dark. [For example], I’m doing a bulletin for the Ford Windstar because we’re getting a lot of calls on that. Nobody [out there] knows what the problem is: the alternator light comes on but it turns out that it’s not the alternator at all but a leaking vacuum line,” continues Buss.

“We’re getting a lot of the bulletins available through the APRA as well as our own sources and we’ve been releasing them on our website as they become available. I think we’re up to 150 or so. We’re trying to word them ‘politically-correctly,’ but [when it comes to tech bulletins] you’ve got to watch out when servicing the vehicle.”

On the whole, the technology behind starting and charging systems hasn’t changed a whole lot over the last decade. However, it’s smart to keep those technical bulletins on hand when dealing with your technician customers, and be apprised of any new developments to come out of OE as new vehicle models drive off the line.

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Vehicle-Specific Electrical Faults

While there are common general faults across all starting and charging systems, there are also faults specific to some vehicle makes and models. Knowing these faults can give you that extra edge when it comes to supplying your technician customers. Here are three such examples:

Chrysler Neon / Voyager -The Chrysler alternators normally fitted to most Neon and Voyager models have unusual wiring comprising a main 8mm stud terminal and a round or oval plug with only one or two pins. These alternators continuously overcharge in excess of 17 volts (the normal charge rate is between 13.5 and 14.5 volts) and are then regulated by the vehicle’s ECU (Electronic Control Unit). The alternator is very rarely at fault and any poor charge rate is due to an ECU or vehicle fault.

Ford Escort and Fiesta -Ford Escort and Fiesta models from 1992-2000, when fitted with a Mitsubishi OE alternator, have all shown the same overcharging problem. Replacing the alternator will not cure the problem. The vehicle is fitted with a fuse link that in most cases breaks down and goes open-circuit; this then tricks the alternator into thinking the battery is low and demands full output to compensate. Replacing the fuse link normally cures the problem.

Fiat / Marelli -Most Fiat / Marelli alternators suffer from a slipping fan belt. This is incorrect
ly diagnosed as an alternator fault when actually correct tension or a replacement fan belt is required. A slipping fan belt can cause the pulley to become hot and red-rusty. Contrary to popular misconception, not all slipping fan belts squeal. Most slip quietly.

Special thanks to Dixie Electric for these tech bulletins.