Internal Pressure Measurement for Sealed Electrical Connectors on Automotive Wire Harnesses: A method to improve Seal Plug Design 2013-01-0398

Real-time pressure measurement inside sealed electrical connectors has been achieved using a new experimental approach. This approach has significant benefits to designers of connectors and the seals used to waterproof the connectors. The seal designer needs to know what pressure is in the connector but until now, pressure measurements were inaccurate due to the slow response time of the equipment. The result was that a peak in pressure of less than 1 second duration would be not recorded. This lack of accurate pressure data has resulted in overdesigned seal plugs - to compensate for the unknowns in testing - and potentially connectors that do not seal as well as required. With the new experimental technique described in this paper, data sampling rates have been increased to 100 samples per second with high accuracy. The new technique uses a portable micro pressure transducer that has been repackaged to fit where a connector wire normally fits.

Invention of this instrument benefits the automotive industry by providing a tool that determines the actual pressures experienced inside a connector and allows for correlated specifications to be written. The most immediate benefit is that seal “plugs” used to block unused terminal cavities can be engineered to assure they will stay in position without overdesigning and making assembly difficult. In the past, plugs were at risk of moving out of position if the pressure was incorrectly predicted to be lower than the actual pressure. This development has improved automotive sealed connector robustness; use throughout the automotive connector industry is expected.