july2023 - 16

» The purpose of electrical diagnostics is to ensure that technicians deal with the root cause of the problem, otherwise a quick fix may cause new issues.
Diesel Laptops
» A good electrical diagnostic kit needs more
than just a digital multimeter. It should
also include safety tools and hand tools.
Peterson Manufacturing
Quick fixes are only a
short-term solution
When lights go out on the road, a quick roadside
fix may require butt connectors or terminals,
noted Larry Rambeaux, sales application engineer,
Purkeys. " However, generic connectors are prone
to water intrusion and corrosion, so they need to
be replaced, " he said.
Rambeaux went on to provide an example of
issues with roadside repairs involving liftgate
charging systems:
A technician moves the wiring until they get
Electrical workstation essential tools
Here is a list of common
tools that should be
readily available to complete
lighting repairs:
* Safety glasses and gloves
* Needle-nose and
slip-joint pliers
* Wire strippers (10-24 gauge)
* Crimping tool
* Heat gun with shrink
tubing (various sizes)
* Utility knife
* Multimeter
* 12V power supply
* High/low amp clamps
* Insulated splice with solder
* Electrical tape
* Potentiometers with
different resistances to
substitute sensor values
* TMC RP 186 Wire and
Cable Repair Guidelines
a light and assumes it's working, but that doesn't
mean the system is charging. In order to hurry
the repair along, the technician may change the
liftgate batteries, but if the charging system wasn't
repaired, the new batteries will drain and cause
another issue.
To verify complaints, Pinter recommended
hooking up the trailer to a tractor or a trailer
testing unit and inspecting all lights. " If no other
issues are found, use a multimeter and check for
power and ground at the light, " he said. " If either is
missing, work your way back through the harness
until the problem is found.
" If everything measures correctly with a
meter, use a circuit loading device and verify
the wiring can carry the load required, " Pinter
16 Fleet Maintenance | July 2023
continued. " A partially damaged wire may give
you correct readings when no load is on it but
fail if trying to operate something. If the load
test fails, move the ground to a known good spot
and test again. If it still fails, the problem is in
the power supply. If it passes, the issue is with
the ground circuit. "
Finally, Pinter said to use an external power
supply to put energy directly to the light and verify
if it operates.
Follow established guidelines
Follow TMC RPs for effective diagnostic and
repair procedures, Rambeaux advised, including
several that show proper wire repair procedures,
how to select the right kind of wires, etc. RPs also
apply to setting up lighting and electrical repair
workstations.
" If TMC RP repair procedure guidelines are
followed, " he added, " fleets can use them and
established procedures to successfully repair
electrical systems. "
For related content go to
FleetMaintenance.com/in-the-bay

http://www.FleetMaintenance.com/in-the-bay

july2023

Table of Contents for the Digital Edition of july2023