Firstly, let me state that in my past I’ve built and flown 3 full size aircraft, built and maintained several race cars…and am still on this planet to talk about it.
I mention this because what I intend to do requires some switch modifications that I have the ability and resources to accomplish.

Not making these mods and using the switch improperly could have serious consequences.

So, as they say, but not in Latin…Buyer be aware.

As stated earlier I went to boat this morning, and as Warren mentioned in his post, the motor will reverse if power is put to the spare terminal. This was easy to test.

Did an Internet search for heavy duty battery switches, and kept coming back to a battery selection switch as we all have in our boats. Stopped at West on way home and for about $40 picked up a Blue Sea m-Series