Professional_Tool_And_Equipment_News_February_2020 - 28

cause extra load on the relay, we used our
RRR machine to service the A/C system.
The system was not overcharged.
After we replaced the relay and verified the system was functioning correctly, we released the vehicle back to
the customer and that was the end of the
story - for about 18 months. Then, the
customer called us and said the words
we all hate to hear: "My car is doing the
same thing again."
When you hear those words, whether it
is the day after a repair or 18 months after,
it is important to respond to the customer
in the same manner. "We will take a look
at it and let you know what is causing the
problem." Then you start the diagnostic
process in the same way you did the initial
repair: without making any assumptions.

PERFORM INITIAL
TESTS, DUPLICATE
THE ISSUE (AGAIN)

Even though this vehicle had not had an
issue even remotely the same as we had
repaired 18 months earlier, we treated it as
a possible warranty/same issue. We started by performing all of the initial tests
again, but this time the thermal imager
showed no excess heat being generated
by the A/C compressor relay or the relays
either under the hood or dash.
We connected the Fuse Buddy between
the positive battery cable and the battery
to measure and test for any current flowing. After connecting the tool, wait whatever period of time is necessary for the
vehicle system to recharge any memory
functions prior to reading how much current is flowing and determining whether
it is within specifications. The test we performed showed a current draw of nearly
2A, well over what is normal.
We have found when we need to
isolate the source of a parasitic draw,
the Cal-Van Tools Amp Hound 2 is an
easy and quick tool to use to locate the
source. The Amp Hound consists of a
small box with a screen with a digital
readout and a pair of test leads. The kit
comes with adapters to replace most
fuses in order to read how much current

PTEN

FEBRUARY 2020

is flowing across the circuit. The tool
also allows you to connect directly
across each fuse without removing it
to obtain readings. This can save huge
amounts of time when you are trying
to determine which circuit has a fault.
After testing, we isolated the current
drain to the audio circuit. Naturally,
since this vehicle has a premium sound
system in it, electrical issues within the
system can be caused by numerous components. Components that are utilized
in this system go well beyond a radio
and amplifier. The steering wheel has
buttons that control some functions,
the GPS is part of the system, and it is
a major part of the CAN bus system. If
you are familiar with a CAN bus you'll
know that some problems can show up
in one module even if the root cause of
the issue is in a different module.
After using the system layout and wiring diagram in Mitchell 1 ProDemand, we
used the Real Fix database function. We
don't always use this feature, but in cases
like this one, it can save hours of testing
components by supplying information
from other shops that have had the same
issue. Don't get me wrong, this does not
give you a green light to replace the components that a Real Fix solution gave you;
it just allows you to start your diagnostic
tests at that component, rather than working your way through the entire system.
There were a few posts about the Acura
that had the same issue where the repair
consisted of disconnecting the handsfree link module. If the flow of current
stopped, replace the module.
We replaced the module, retested the
system, and found no further issues.
It is important to invest in tools that
are engineered to save you time and
provide you with accurate and repeatable results. Those tools, along with
good information and a logical testing
process will allow you to efficiently and
correctly repair vehicles. Remember, the
primary thing we sell is time. Anything
you can do to sell more time will make
you more money, especially if it is a timesaving tool.

www.VehicleServicePros.com

RELATED TOOLS
FOR THIS REPAIR
Mac Tools
Digital Multimeter,
No. EM721

Circle 84 on card, or
enter at "e-inquiry" on
VehicleServicePros.com

Electronic Specialties
Fuse Buddy
Circle 85 on card, or
enter at "e-inquiry" on
VehicleServicePros.com

Launch Tech USA
Thermal Imager

Circle 86 on card, or
enter at "e-inquiry" on
VehicleServicePros.com

Associated Equipment
Intellamatic Smart
Battery Charger and
Analyzer
Circle 87 on card, or
enter at "e-inquiry" on
VehicleServicePros.com

http://www.VehicleServicePros.com http://www.VehicleServicePros.com http://www.VehicleServicePros.com http://www.VehicleServicePros.com http://www.VehicleServicePros.com

Professional_Tool_And_Equipment_News_February_2020

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