Referring to the above drawing, see where the pink wires attach to new relays? There's a splice somewhere in that circuit.
See the new heavy gauge power wires connecting between the ammeter & the ignition switch? That's one possible connection, you could connect directly to the battery positive terminal also.
Everything "to the right" of the fuse box and below the fuse box is new wiring, abandon the old stuff. I mounted the fuses in the front trunk, in the front of the trunk, just behind where the oem fuses were mounted. Mounting them in the front trunk keeps the wiring & relays out of the elements. That was my preference. The SPAL relays are sealed very well and could be mounted in the oem location if that's your preference.
Grounding the fan motors and the temp switch requires a bit of additional wiring and some crimp terminals.
-G