The way it used to be

By Jim Taylor, Editor MACS ACtion Magazine

MACS member Gary Wrench is vice president at Omega Environmental Technologies. He’s been in the business a long time, and had a successful prior career with Frigiking, one of the pioneering providers of A/C in the 1960s and ‘70s. This of course was back in the day when air conditioning, particularly on imported cars, was an aftermarket installation and not factory-standard.

Air conditioning was rare in Europe, but all the carmakers realized it was a virtual requirement to succeed in the U.S. market. Some domestic makers used external units as well, and  Gary notes that his former  company made “factory” A/C units for Mercedes-Benz, Volvo, Nissan, Chrysler, Honda, Aston Martin, Fiat, Jeep and others.

Gary recently came across the Operators Instructions for one of the early OE-approved Frigiking units  made for the Mercedes-Benz 200 series cars, both gas and diesel. Some would argue that the late 1960s through mid-70s marked a high point in Mercedes Benz quality and performance.  Many cars from that era remain very popular in the collector community as well as some still being in daily service.

Being selected as the factory supplier for North America was quite a coup for Frigiking, and having air conditioning in your new Mercedes was frosting on an owner’s cake. The add-on air conditioners could be installed by either the dealer or at an independent shop, and of course used R-12 refrigerant. If the installation warranty card was sent in within 10 days, Mercedes-Benz dealers would honor the Frigiking warranty.

 This unit was for the 280SL model, but others were similar. Note the “foot area” outlet; many units were installed in convertibles and could be used even with top down.

Some of the instructions for the user are interesting in light of today’s technology. For instance, all units offered “city” or “hiway” knob positions. We think the “city” position was what we know today as “recirculate,” which cuts off the outside airflow. Regardless of model, the instructions provide some version of “Turn the air control [fan] to the desired setting, then adjust temperature control to coldest “City” setting if maximum cooling is needed.”  Sounds just like what we do in today’s cars, non?

After switching to the “hiway” position, operators were reminded that “At prolonged high speeds, the compressor capacity is normally more than is needed and ice may form on the evaporator coil. Icing is readily noticed by a marked decrease in air velocity. To overcome this condition, turn the temperature control to the off position. As soon as the coil is clear and normal air delivery is restored, adjust the temperature control to the ‘hiway’ position.” When was the last time you saw that happen?


On the other hand, some of those 40 or 50-year old rules still apply today. The General Service Recommendations advise, “Do not use a bug screen in front of your radiator or condenser. This will create an air block and cause engine overheating and impair the cooling capacity of your air conditioner. Clean leaves, dirt and other matter from the condenser regularly. A soap solution is recommended.”

The more things change, the more they stay the same. Thanks Gary, for the time trip and reminding us of our roots..

Few cars were prettier than the SL series of Mercedes-Benz sports cars. This is a 1965 230 SL roadster, photographed by the owner, Alf van Beem.

The Mobile Air Conditioning Society’s blog has been honored as the best business to business blog in the Automotive Aftermarket by the Automotive Communications Awards and the Car Care Council Women’s Board!

When having your mobile A/C system professionally serviced, insist on proper repair procedures and quality replacement parts. Insist on recovery and recycling so that refrigerant can be reused and not released into the atmosphere.

If you’re a service professional and not a MACS member yet, you should be, click here for more information.

You can E-mail us at or visit to find a Mobile Air Conditioning Society member repair shop in your area. Visit to find out more about your car’s mobile A/C and engine cooling system.

The 33rd annual Mobile Air Conditioning Society (MACS) Worldwide Training Conference and Trade Show, Be the Best of the Best will take place February 7-9, 2013 at the Caribe Royale, Orlando, FL.


About macsworldwide

Mobile Air Conditioning Society (MACS) Worldwide Founded in 1981, MACS is the leading non-profit trade association for the mobile air conditioning, heating and engine cooling system segment of the automotive aftermarket. Since 1991, MACS has assisted more than 600,000 technicians to comply with the 1990 U.S. EPA Clean Air Act requirements for certification in refrigerant recovery and recycling to protect the environment. The Mobile Air Conditioning Society (MACS) Worldwide’s mission is clear and focused--as the recognized global authority on mobile air conditioning and heat transfer industry issues.
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