Dang John, you make it look easy
I'm not %100 on why two, or how to wire them up though. In series I presume, for a larger signal?
Oh, and obligatory drawing of what came to mind when I saw the pic
Harder to manufacture but should be able to clamp down harder w/it.
P.S. we should probably keep the diesel stuff in this thread. Hate to see you guys having to type everything in twice.