With its A/C and fan switch experience, the company saw a cost-reduction opportunity for its heavy truck customers in the early 1990s. A pressure switch in the air conditioning system frequently turns on the cooling fan to reduce A/C pressure. However, an A/C fan switch operating alone can cause the fan clutch to cycle rapidly, causing premature clutch wear and tear and excessive noise. Index engineers recognized that more "intelligence" was needed in this link between the A/C system and the cooling fan, and invented the K7 Fan Control Kit. When engine cooling is needed, the temp/timer control acts as a typical fan control switch. But when triggered by the A/C pressure switch, the control runs the fan for three minutes. This greatly reduces overall A/C system pressures and fan cycling frequency, and extends system life.

The value of Index's innovation in fan control timing was so widely recognized that A/C-triggered fan timing was incorporated into all Engine Control Modules (ECMs) when they were introduced in 1994.

Inquiring further with truck fleets about their A/C system experiences, Index saw great potential to reduce high A/C maintenance costs associated with issues such as frustrating troubleshooting and frequent replacement of clutches and compressors. In 1995, following extensive testing and analysis, the company introduced APAds (Air Conditioning Protection and Diagnostic System), a "smart" control system that extends the life of many A/C system components. APAds suspends A/C operation under harmful pressure or voltage conditions, ensures regular system lubrication, and provides diagnostic fault codes that reduce troubleshooting and maintenance time. A 9-million-mile field test on over 100 trucks showed A/C maintenance costs on trucks with APAds were up to 64% lower than on trucks without the system.

Since it was introduced in the mid-1990s, more than 500,000 APAds systems have been installed on trucks in North America, either as standard equipment or as a spec option. A similar product, the AC-X10 Air Conditioning Life Extender, was introduced in late 2002. The AC-X10 offers the protection benefits of APAds (without the diagnostic features) in an easy-to-install configuration.

Index continues to expand its focus on helping industrial vehicles and equipment OEMs and users add innovation and efficiency to their products. Index's switches, sensors and controls will play a growing role "behind the scenes" improving basic machine operation, as well as benefit equipment users with easier operation, diagnostics, and lower maintenance costs. Extending our horizons, we see a bright future in the electric vehicle scene as we create solutions for new questions that may arise.