april2021 - 20

To make things even more frustrating for
technicians, conditions that can cause electrical
systems failures are often highly intermittent in
nature, explains Jason Hedman, product manager for Noregon. For example, he notes, a wire
that is wet may carry a current just fine when
it is dry. Likewise, a failure caused by a wiring
harness vibrating rapidly at highway speeds may
be undetectable when the truck is sitting still
in the shop.
" This aspect of troubleshooting electrical
systems has always been particularly challenging for technicians, " Hedman says. " A problem
can occur on the road, and be faithfully reported
by the driver. And then it can't be replicated in
the fleet shop or at a third-party service supplier.
Technicians can spend hours crawling over and
under a truck trying to figure out what the issue is. "
That's assuming you're even working with the
wire or component that's actually experiencing problems. As LaPage points out, trucks are
mass-produced consumer items that can be spec'd
with many different electrical options.
" Working with wiring is always easier when
you have a nice, clean system on your hands, "
she notes. " But within any wiring harness, there
are almost always wires for optional or deleted
systems that are not being employed at all. So, for
many technicians, half the battle is often simply
figuring out which wire they need to focus on. "
" Electrical system troubleshooting is a massive
time suck for fleets, " agrees Brett Miller, engineering manager, Optronics International/
USA Harness International. " A big problem is
that many of them are still using old methods
to determine what the issue is. But sticking a
probe through a wire casing to see if current is
getting through ultimately creates more points
of entry for water, dirt, and other elements that
can eventually compromise an entire wiring
harness. Fleets really need to adopt better ways
of understanding what problems they're facing,
instead of spending excessive time casting
around and hoping to hit on the issue - which is
what happens most of the time. "
" Historically, corrosion has made testing
components difficult for two reasons, " says Cory
Adams, vice president of engineering, Peterson
Manufacturing. First, he explains, separating
corroded components can be difficult and sometimes impossible without breaking the connectors
and components. " And second, " he says, " trying
to find a damaged wire across hundreds of feet
of wire on a trailer is tedious and time-consuming which causes extended trailer downtime and
increased cost to repair. Checking each and every
wire in a system while trying to track down electrical issues can prove to be quite laborious.
" Additionally, when moisture enters a wire it
spreads across the entire system by the capillary
effect, " notes Adams, in reference to the ability
of a liquid to flow in narrow spaces without the
assistance of, or even in opposition to, external
forces like gravity.
All of which means damage to one wire can
cause corrosion across the entire system if given
enough time.
" Technologies, like Peterson's Integrated
Moisture Barrier, that limit this propagation

20 Fleet Maintenance | April 2021

»One good strategy for mitigating electrical issues is to periodically check all connections and plugs on
a fleet's vehicles and replace them with newer, more weather- and corrosion-resistant components.
Photo courtesy of Peterson Manufacturing

»Plugs and connectors are a common weak link in vehicle electronic systems.
Photo courtesy of Optronics International

»One approach for cutting down on
electrical issues is to adopt a dedicated PM
program and swap out older style plugs
and connectors for newer ones that offer
greater protection from the elements.
Photo courtesy of Optronics International

of moisture can reduce the damage caused by
moisture entering the system at a single point, "
Adams says. " Additionally, harnesses that are
modular allow the technician to replace the
damaged wire in a quick and easy way, saving
labor hours and stopping the wicking of moisture to other components including your lights. "
Another problem is that new technology
often means relearning maintenance truisms
and procedures that have been in place for
decades. A good case in point, the introduction
and fast adoption of new LED lighting systems
on trucks has unintentionally created maintenance headaches for some fleets, says Kyle
O'Dell, director of engineering and new product development, Optronics International/USA
Harness International.
" The issue is that conventional, incandescent
light bulbs draw more power than LED bulbs -
which is one of the key benefits to switching over
to LED systems, " O'Dell explains. " However, some

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