"AJH" wrote in message
...
I have a Chevy Astro with a 8 wire harness, can I use the blue auxiliary
wire for a boat winch that has wires rated for 30 amps?

FWIW, I have used a winch loading a salt water flats skiff for many years. I
was told by the winch manufacturers, Powerwinch Inc., to run a set of 6
gauge wires from the battery as a separate circuit. I would put a 40 amp
circuit breaker at the battery also. Winches use a 12 volt high amp motor
and I doubt if your harness would carry the load.
My 2 cw.