Trolling motor wiring

[brgbassmaster]

So I'm putting new trolling motor on boat. right now it is a motor guide brute 767. I unscrewed mounted foot pedal to see how it was wired in and noticed 3 wires a black, red, and white? Now the motors Im looking at is the minnkota edge 70lb and the motor guide x3 70lb. Both have just two wires a black and a red. Not really sure how to do this now. I've installed motors before with just two wires obviously just plug and play. But my electrical skills are SLACKING. Thanks for any help. 

[Jig Man]

Your motor has 3 wires because it is a 12/24 volt so you can run either 12 volts or 24 volts.  A straight 24 volt trolling motor only needs 2 wires because the batteries are hooked up in series.  You just need to find out which wires are the series wires and then don't use the wire that has the parallel hook up for 12 volts.  You will be able to tell this where they are hooked to your batteries.

 

If you can't figure it out post a pic of the battery hook up.

[Way2slow]

Check the wiring in the boat.  You will probably find four wires going from the TM back to the battery, hopefully #6 gauge but could be #8 or even as small as #10 (bigger the number, the smaller the wire).   If it's #6, you have something you can work with, if smaller you will need to replace it with at least #6 or better with #4 to run the larger TM's you plan to use.  You will also need to replace the circuit breaker/breakers on the battery.  The one you have may be as small as 30 amp, you need to get the Buss/MinnKota 60 amp breaker (cost about $30), so you are looking at about $100 worth of upgrades to wiring.  You may as well get you two Anderson SB-50 or SB-75 connectors also if you plan to install the new TM with quick disconnects.  Make sure to get the ones to fit the gauge wires you are connecting them to.

 

Now, you can save a little if your boat has #6 gauge wire by just connecting each pair in parallel, that will give you the equivalent of the next size larger wire.

 

  DO NOT use them as they are installed for 24 volt use.  That's approx. 100 feet of wire length the current will be going through and cause you a large amount off loss.  No need going to that bigger motor if you are going to throw half of it away in cable loss.

[WRB]

1. Change the wiring to 6 or 4 gage.

2. Add a pair of connectors, plug and receptacle  and access panel at the bow, do not hard wire direct, good advise above!

3. Add new breakers 50 amp for 24V is OK, 60 amp maybe better.

4. Add a 50 amp cranking battery switch to isolate the battery when charging.

Been a long time since seeing a Brute 12/24 TM!

If you are not skilled doing this, take it you local bass boat dealers shop.

Tom

[Way2slow]

I think a battery disconnect switch needs to be larger than 50 amps.  You have to remember, even when a smaller motor is cranking over, it's pulling over 100 amps and larger motors can be pulling 200-300 amps.  Too small of a disconnect switch can cause the starter to spin slower, and you really want it spinning as fast as possible. Plus it's dropping the voltages going to the ignition, something else you don't want. 

[WRB]

16 hours ago, Way2slow said:

I think a battery disconnect switch needs to be larger than 50 amps.  You have to remember, even when a smaller motor is cranking over, it's pulling over 100 amps and larger motors can be pulling 200-300 amps.  Too small of a disconnect switch can cause the starter to spin slower, and you really want it spinning as fast as possible. Plus it's dropping the voltages going to the ignition, something else you don't want. 

That ls all I have used with engines up to 200 hp, never noticed any issue starting. Need to look at the switch a make sure what I have, getting old!

Tom