Yeah no offense but your wiring is a bit dodgy
You dont need to earth back to the battery terminal, just use a short wire to the car body. Also a high current relay with a low current switch is better than a single high current switch.
You should also be able to simply push a number of bolts through the radiator fins and use a wide washer on the other side to secure the fans
Did you wire the fans in series or parallel?
They look like they fit nicely!
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SilviaWA
1992 180SX: cwest, vertex, wise, pivot, gemax, embleton, kyb, blitz, whiteline