i totally understand what your saying, but as i said pal, had exact problem as our friend, and i changed starter, alternator, unwrapped all wiring to find the fault and thats what it was, so just saying, before you under take everything else, just try that, the sensor is pennies and will save a total fuck on changing the rest..........
would stick my ore in normally, as i'm no mechanic, but is a prob i had last year that confused every fooker that looked at it........