O.K. I know this sounds strange but it is true. A friend and his wife both have Tour Master electric vests. Hooked directly to the battery with the harness that was supplied with the vest. He purchased a Y connector so they could both plug into one lead from the battery.(the connector has an in line fuse and it has never blown) The vests will not turn on if he starts the bike first. If he turns the vest on while the bike is off and then starts the bike both vests will work while the bike is running, but if either one turns their vest off while the bike is running the vest will not turn back on unless the bike is shut off. The vests have a connection that goes to the battery for power and a separate control for the heat, high med low and off. We were on a three day ride and this happened all 3 days. The vests are new, his was replaced because his controller was bad on his last one and this is the first time he has used his new vest.