The two outer red are common and the two outer blacks are common. OR to say it another way. The two outer pins/wires are for the discharge leads(red and black) Even though the equinox has 5 wires it only uses 3 of them when it connects tio the adapter for Align taps. The Align tap should only be a 3 pin connector.

I am guessing that perhaps you have the hi-power adapter instead of the regular one. If so it has two loose wires (the two outer ones) that get hooked to the pack's discharge lead.

Are we sure that the Losi comes with the JST, electrifly, align,XH, type taps? It is a rectangle female with two tangs on one long side and uses a (cell+1) config. The male connector looks like a rectangle jack-o-lantern mouth with a set of teeth (cells +1 config) that would be 3 teeth I think.