Don Mahony wrote:
I am installing a Lewmar Horizon 600/900 horizontal windlass on a 27
foot power boat. The users manual says to use #4 AWG marine grade wire
from the battery to the solenoid to the breaker to the windlass and
back to the battery. The wire leads on the windlass are #10 AWG.

I know the concern here is with voltage drop to the motor but the cost
of the #4 wire is huge. Rather than following the general guidlines in
the manual does anyone have a better way of calculating exactly what
gauge wire would be needed for this installation?

The total run from the battery to the windlass and return is 72 feet.

Don

We got round this by using the engine starter battery and positioning it so
that it was as close to the windlass as possible (up forward) but still had
enough power to operate the starter. Easy on a 50-footer, but I don't know
about your 27-footer (storage space for the battery).