Hi there,
OK, well there is no specific test or calculation to determine the life of any electrical component, there are to many variables, extremes of temp can play a part, but its really just luck of the draw so to speak, other things that can cause premature failure are over charging alternators, voltage spikes, bad earths.
Mark (mhpautos)
Monday, April 12th, 2010 AT 7:34 AM