the wire going INTO the switch does not need to be 10 gauge. 18 gauge would be fine.
you should be able to sneak an 18 gauge WITH the 10 gauge wire into the connector (2 wires into 1 connector) that will go onto the relay of pin 87. and run that 18 gauge wire to the switch IN and you can run 18 gauge wire to the relay trigger pin 86.
that should make it easier to do.
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1994 Honda civic CX hatchback (BIG MPG) STAYING STOCK
*******1999 GT SOLD*****