Hi, Great website!

I have a 1986 Champion 201 Super V which had an old Mercury 12/24v TM & a pro charge panel on the bow with a (charge, 12V & 24v toggle switch. This set up has two 10 guage positive & two negative wires form the batteries on the stern to the bow. The batteries are installed in parallel & the toggle switch at the bow is used to (charge, 12v or 24v).  I am going to install a Minn Kota 80# Ultrex & a Minn Kota MK 330 PC on board charger.

1-Should I connect the two 10 guage positives & negatives wires together & use as a two wire system with a jumper on the batteries to install in series?

2-Replace the four 10 guage wires with two 6 guage wires with a jumper on the batteries to install in series?

3-Leave the system as is?

Thanks so much for your advice!!

By my calculations,  two 6 AWG wires would be 26% better (less resistance) than four 10 AWG wires connected as you described.  Given the age of the wires and the reduction in voltage drop you would see with 6 AWG,  I would rewire with 6AWG.

What should I replace the plug with? Thanks!