i had the same problem some time ago. In my case it was a shorted out battery
but If think in your case the battery connection probably was loose. The hold
down bar came loose and momentarily shorted out the battery. As I pulled off
the road, the pot hole bumped the bar free and all was well again in
Spriteland. I have an amp meter and it showed big time discharge as I was
pulling off the road. BTW, the amp meter is a repro Model A Ford
item,--small, cheap , and in keeping with the style of LBC.
My 2 cents worth,-------------Bob Chamberlain