The complexity of modern car air conditioning or climate control can sometimes result
in a failing AC system that will not respond to just a routine vacuum and recharge
service. In these circumstances the requirement is for good observational skills
to detect operational abnormalities, extensive vehicle data files to act as
a reference point, a wealth of AC experience and an analytical brain to utilise
these factors and come up with the solution.
Our first response to an electrical fault is a Power Probe and a Digital Multimeter.
Increasingly however electronics rather than just electrics are responsible for many
problems and additional tools have to be be employed. Electronic Diagnostic Tools, able
to communicate with the onboard computers controlling much of the cars operation are
necessary for virtually all post 2000 vehicles. These identify and can remove Fault Codes
that have been generated by the onboard computer network in modern vehicles. Fault
Codes are not always generated however and in these cases we have to dig deeper to
find the problem.
We also use a Multi-channel Oscilloscope to observe the actual waveform generated by
whatever control module in the car we are investigating. To complement that we have
a variable width squarewave generator to simulate the action of the AC Control Module
as it controls the latest generation of AC compressors or stepper motors. In the hands
of an experienced technician these pieces of specialised test equipment are invaluble
and can help diagnose most problems but if the brain behind the tool is inexperienced
the outcome may be disappointing.
In the process of investigating AC faults our High Tech equipment can sometimes reveal other related Fault Codes and sometimes Fault Codes completely unrelated to the AC system can be detected which we are often able to correct. For example a problem with a rear door window motor in the past may have generated a Fault Code which may prevent the central locking system working correctly. This may be identified in the process of investigating an AC fault and can be corrected simultaneously.
To be frank, some of our most testing electrical problems have been very low tech - they have simply been the result of a bad connection, sometimes badly corroded or a wire actually broken. Mostly we can find these but sometimes we are forced to refer these to another specialist, an auto electrician.