The degradation of road tested automotive connectors

The increasing amount of telematic and other electronic systems in the modern motor vehicle demands high performance and reliability in ever decreasing space. The automotive connector is well known to be the weak link in electronic systems due to the multi-environmental conditions seen in the motor vehicle. These conditions of large temperature changes, high humidity, and corrosive atmospheres have significant and varied affect upon the connector. Sample signal and power automotive connectors which are currently undergoing road testing, are being monitored to evaluate stress levels during real operation. Environmental conditions such as, temperature, humidity and vibration levels of these connectors are being monitored in situ. Connector temperature data from vehicles operated in the United Kingdom is presented in this paper. An empirical model is also presented demonstrating some of the general features of connector temperature behaviour. Scanning electron micrographs, elemental analysis and contact resistance measurements are also taken to determine the level of degradation of these connectors. Evidence of fretting corrosion was found at the contact interface on tin plated terminals from sealed and unsealed connectors; however gold terminals exhibited minimal wear.