my mistake Cletis, I read your post and missed the idea that the common was the ground (or actually, in this case..the missing ground). I now understand that if the ground was ok the lights would flash normally but without the ground the current continues on thru the second filament in search of a ground further on. This scenario would continue until a ground is found. All affected lights will be lit but dimmer than normal (because of the increased wattage on the circut???) It is a concept that is a little difficult to understand but as Stuart suggested, a hand drawn picture makes it easy to see.
Thanks Cletis and Stuart for explaining this strange circut, I may need this info myself one day.
