I can't remember all of the original details from that rainy night yesterday that Alistair went through....but in my personal life experience, there is always some kind of bump (however minor) when entering an alley from a street.  Hence, my speculation.  And only takes a minor bump in the road to break an already compromised electrical connection, I know that for sure.   (This whole discussion is so refreshing....given the dire realities happening around us.)

    On Sunday, March 29, 2020, 3:34:34 PM PDT, Gene P <olgreywoof@gmail.com> wrote:  
 
 < But the question still remains...why did things fail after a bump in the road when entering alley?  Maybe we need Inspector Columbo!!...he was always good at this kind of stuff.  (Actually for me as a bone-head novice mechanic, it's super cool to witness experts attacking the problem from multiple angles.) >

Not a master mechanic here, but a sometimes wannabe Columbo – observing that Alistair’s original description of the problem said nothing about a bump in the road.  That was introduced by a response that possibly a turn into an alley involved a bump and then several have speculated about what the bump did.  Speculations about the speculative bump.