And what I meant was that an invisible terminal issue is no surprise at all as a cause for that symptom set. In fact, it may not have even been corrosion, in which case we would both be right. Sometimes the terminal bolts wear right at a certain point and can no longer apply good tension to the posts. The solder joints to the cable can loosen and break with time, heat cycles and vibration. The cable ends can fatigue and break enough tiny strands that full current can no longer pass. Fifteen or more years is a lot of time on a battery cable, if original.