Okay, I went with Minn Kotta and replacing the 1991 motorguide. They both are 24 volt. When I pulled the receptacle out to look at the wiring, I expected to see 2, #6 wires. Nope, I have 4, #6 wires. I think it is because the motorguide is a 12/24 volt. Is it because 2 of the wires are 12 volt and the other 2 are 24 volt? There is a switch on the foot control that toggles between 12 and 24. So I am thinking that I need to find the 2 that are 24 volts and leave the other 2 off. The male plug coming from the foot pedal has 4 wires as well and the plug and receptacle are 4 prong.
I may use the same plug and receptacle if the new one doesn't fit the hole.
Am I anywhere close to having this figured out?
Thanks

I had the same situation when I bought my new to me boat in 2011. I had a new Terrova 24V already so I replaced the existing MG 12/24 with the Terrova. You only need the one that is 24 volts. I had to replace the receptacle in the bow to fit the 3 prong plug of the Terrova though. Or I could have replaced the Terrova plug to fit the existing bow receptacle. Maybe there is a converter for the two types; didn't think of that at the time.

find one 24v and one ground, tape off the other 2 and just use 2 of the prongs on the receptacle. Hopefully the wiring is #6. There should also be a circuit breaker on the 24v line

Thanks for the info, I was thinking I was on the right path. There is a circuit breaker. I should have this thing wired up and installed pretty quick not.

On the wiring side of the receptacle each of the pairs of wires are just 12 volts...... Not 24. For 24v tm it is best to install a short 6 awg or larger jumper in the bilge to place the batteries in series and use the black of one pair and the red now +24v from the other pair, taping off the other two unused wires... It will function, but do not use the above suggested inefficient way of using all 4 wires with the jumper wiring for 24v being made inside the plug up at the bow .

You should use the exact breaker size listed by MinnKota for your model. It should be positioned in your bilge on the +24v wire.

The older boats were wired with 4 wires and used a jumper inside the 4-prong trolling motor side plug. This was before onboard chargers and allowed you to change plugs and use a "charge" plug connected to an external charger and charge both 12V batteries at the same time. This is all obsolete now, and the better way is described above. Remove the positive from one battery and the negative from the other. At the plug, the negative battery cable will go on battery A neg and the positive will be on battery b positive. A jumper will go between battery 1 positive and battery 2 neg.
John

Yep and I got it figured out
Thanks guys