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The reason teh rear is engage independantly is because alot of people will engage the rear locker while in 2wd just to get through mild stuff. NOONE uses only the front to get through anything. (unless of course you have breakage) We either use the read or all so it only make sense to wire it for the rear to engage or all. If we did have breakage and used only the front wheel drive, due to the steering components on a paved road we would want the unlocked feature for driveability, thus not needing a locked fornt diff. If it was a FWD based import with 4x4 they would most likely allow the front to engage first, (based on principles of FWD this isnt possible, but for making a point it will work)
