My last electrical question was too easy - bike electric tricky one!

[Hamos]

You can still have it self contained, you just need to separate your +ve bus bars in the box so you have one that runs off the battery direct and is always on and the other is fed from the switched feed relay.  The negative bus bar can be a common negative for all.

You would have 2 +ve feeds from the battery, 1 directly to the "always on" bus bar and the other to the relay and then onto the "switched" bus bar.  You can wire 2 wires to the 1 connector at the battery terminal and split them off later to keep it neat.  Or just wire from battery to pin 87, then take a wire from pin 87 on relay to the "always on" bus bar and then wire the rest as per diagram.

You can buy a FuzeBlock that does this job for you,  but it costs £70, however it is one self contained unit.

I can do a wiring diagram for you if needed.