Yes the external earth strap is to take any current from a momentary short to +12v off the socket pin
The basics of it all are in the pdf I referred to in an earlier post and I will be adding further info with pics when we do another one here
The original Rotax single BMSC used on the BM's has a 1/4" spade connector for earth in the socket then an internal strap off the back of the spade connector which connects to the case. Makes life difficult to open up the ECU to replace components but protects the ECU. Those early ECU's survived some real torture when people first started trying to get into the firmware. I have some of them here
The basics of it all are in the pdf I referred to in an earlier post and I will be adding further info with pics when we do another one here
The original Rotax single BMSC used on the BM's has a 1/4" spade connector for earth in the socket then an internal strap off the back of the spade connector which connects to the case. Makes life difficult to open up the ECU to replace components but protects the ECU. Those early ECU's survived some real torture when people first started trying to get into the firmware. I have some of them here