Here's my friendly neighborhood mechanical posting for the month. For some unexplained reason many folks come up to me at truckstops and ask me if I can jumpstart their "dead" batteries. Guess what? In 8 out of 10 instances there is nothing wrong with the batteries at all. When I get an open end wrench out of my toolbox and tighten down all their loose battery cables, their truck fires right up. Especially common on batteries where the cable is secured with a bolt that threads into the battery terminals. Remember this when you hear that clicking noise...