Changes in A/C systems challenge the aftermarket

As carmakers have improved vehicle designs over the years, the aftermarket faces continuous challenges. Nowhere is this more evident than in HVAC systems, as indicated by the results of the recently completed Mobile Air Conditioning Society (MACS) Field Services Survey presented at the MACS Training Event and Trade Show at the New Orleans Sheraton.

Repair shops are seeing a reduction in the required servicing of mobile air conditioning systems, noted Ward Atkinson, MACS 30-year technical director, in presenting the survey results in New Orleans.

As systems have improved, vehicles are not having A/C issues as frequently, says Atkinson. Nor are aftermarket shops seeing the same repairs. Shaft seal leaks on compressors, once a common occurrence, fell since 2003. The most common components responsible for leaks in 2013 were hoses, condensers, service ports and compressor cases.

Refrigerant circuit repairs have become less common since as far back as 1991, Atkinson notes, while non-refrigerant system control repairs have increased since the early 1990s. Techs who plan to remain in the A/C business will need to be better trained, Atkinson observes. They will have to understand the control circuits and the fault codes, not just refrigerant circuits.


R-1234yf takes hold

Then there’s the new R-1234yf refrigerant. R-1234yf will require shops to invest in new recovery, recycle and recharge machines to service vehicles with R-1234yf. The new refrigerant is mildly flammable, Atkinson notes, so service equipment is designed for a new procedure to assure that a potentially leaking system is not charged. In addition, for safety reasons, R-1234yf leaking evaporators cannot be repaired or salvage vehicle units used, and only new SAE J2842 certified evaporators can be installed.

Electric, electric hybrid and plug-in hybrid vehicles are also becoming more popular, posing some unique A/C service considerations. Many electric and hybrid cars have high-voltage electric air conditioning compressors, and some use active air conditioning systems and heating systems to control battery pack temperature.

Some plug-in hybrid and electric vehicles use high-voltage heat exchangers to produce the heat that would normally be supplied to a conventional vehicle’s HVAC system by its engine, and as with conventional hybrids, current leakage to the chassis or the component ground can be a concern. To diagnose such an issue, the service tech needs an insulation resistance tester, also known as a megohmeter, used in conjunction with scan data.

Much is changing in the mobile A/C business. Technicians who want to service vehicles with newer technology need access to repair information and they need to be trained in how to diagnose these vehicles. They also need access to the most current diagnostic and repair tools.