United States Postal Service route delivery vehicles start and stop dozens of times per day on some routes. Because of this extreme duty, and the long life of the vehicles, the ignition switches in theses vehicles were failing. Worse, the failure mode would burn up wiring harnesses, and sometimes even cause vehicle fires. In response, the USPS was preventatively replacing the ignition switches in their entire fleet of these vehicles at least annually- costing them over $3 million per year.

Questek developed a module, called an Ignition Switch Circuit Interrupt Device, that was inserted between the ignition switch and the wiring of the vehicle. This module performed several functions to:

• extend the life of the ignition switch
• prevent wiring damage and vehicle fires in the event of switch failure
• provide diagnostic information, via a series of LEDs

As a result, the U.S. Postal Service was able to stop fleet wide preventative replacement of the ignition switches- saving them over $3 million per year.