Trouble Shooting Trolling Motor

[gone2long]

I'm trouble shooting a minnkota maxxum trolling motor I got with a boat I just purchased. The previous owner was up front with me that during prolonged or extended use the inline fuse would blow but I noticed he had spliced a 12 AWG lead with inline fuse now I'm no electrician by any means but it sure looks like the main wire for the motor is much larger and I was wondering if this lighter gauge wire could be the problem, does anybody know what gauge the factory puts on their motors? Also read that if you hand tighten only on the battery that that could cause an overheat arc issue which could also blow a fuse any takers on that question?

Thanks in advance for any assistance offered,

Chris

[archeryrob]

I do electrical control work. They usually up size wires to trolling motors much larger than I would expect them to be. If you saw it in a house you would expect it to be for a 50 amp electric stove! That trolling motor draws nothing similar to that. The small wire is most likely not the problem. Hand tightening wires can be fine, but is the problem as they vibrate loose and loose makes a bad connection which make resistance, which can make blown fuses and poor circuits.

The problem can be any where and some that understands and has a meter should check it. Poor connections or the motor are usually to blame. Poor connects ussualy make an open, not a short and shorts are what blow fuses. You have a motor drawing more current than it is supposed too, or too small of a fuse. What amps are the motor rated for? 5 amps and you should have a 10amp fuse, even a 20 would be fine. Short cycling a motor can blow fuses too, on, off on off very fast heats the fuse and makes it melt.

Many things can go wrong and it's hard to tell without better info on this side of the computer. I'll ty if you get some more info.

Edited May 6, 2011 by archeryrob

[bombadier]

I'm trouble shooting a minnkota maxxum trolling motor I got with a boat I just purchased. The previous owner was up front with me that during prolonged or extended use the inline fuse would blow but I noticed he had spliced a 12 AWG lead with inline fuse now I'm no electrician by any means but it sure looks like the main wire for the motor is much larger and I was wondering if this lighter gauge wire could be the problem, does anybody know what gauge the factory puts on their motors? Also read that if you hand tighten only on the battery that that could cause an overheat arc issue which could also blow a fuse any takers on that question?

Thanks in advance for any assistance offered,

Chris

Take the prop off and look to see if the seal around the shaft is compromised in any way. A piece of fishing line or whatever might be letting in a little amount of water and causing the fault. If you can't tell just by looking at it remove the two screws and pull the end of the housing off and look inside for any signs of water in the housing.

[hillbilly1]

The back of my boat looks like radio shack exploded I have 4 bats. wired 2 in series and 2 in parallel I pull 24v to the bow mount and 12v to 2 minns. on the back . In a rule of thumb the further away the draw is away from the power source use bigger gauge wire. The ones closest to the bats. I use the stock I think 10ga. but with the bow mount I have 8 ga. with a 60amp breaker on the + lead and never had any issues. Like the other post check around the shaft for line or something restricting the rotation. I had one minn. the internal magnet came loose and was rubbing on the rotor it would blow a fuse every time I would run it and get real hot on the housing. Spin the prop with your finger (unplugged ) and see if it spins freely or is dragging.

I re read your post if the 12ga is running from the bat. to the in line fuse then to a larger ga. wire that may be the problem. IMHO run 8ga from stem to stern both +/- with a breaker that way you wont run out of fuses

As for the other most terminals used for hand tightening are just thin copper if you are pulling 24v on 8 to 10 ga from transom to bow at full speed for X amount of time the flow of electrons will get compressed and have to fight for through put at the gauge drop point thats why I over size with 8 ga. and normal big ole honkin lead terminals from the N A P A

[Braided Line]

Take the prop off and look to see if the seal around the shaft is compromised in any way. A piece of fishing line or whatever might be letting in a little amount of water and causing the fault. If you can't tell just by looking at it remove the two screws and pull the end of the housing off and look inside for any signs of water in the housing.

As stated,water getting into the housing will sure create a problem. Along with other situations as well.

[powerworm]

there is no need for any fuse of any type on your main wiring for your TM but a good resttable 50 amp breaker will alert you to problems hopefully while they are small enough to be fixed inexpensively

[Musky Glenn]

A # 12 wire is generally used for up to 20 amps. You didn't say how many amps your trolling motor pulled under full load. A good electrician needs to give us some correct information concerning correct fuse size and wire size. It also matters if it is being 12 volts or 24 volts. How about letting us know how many amps the trolling motor pulls and we can give you some better information. You need a fuse or breaker of some type, but not larger than what the wire will stand and that is 20 amps on a #12 wire. Musky Glenn

[BobP]

Manufacturers equip small boats requiring less powerful TM's with 8 gauge wire runs. For larger boats with TM's over 50 lb thrust, the standard is usually 6 gauge wire. That may seem like overkill but I'm guessing there's a reason. I'd put a 50 amp breaker on the battery and run the factory line (8 or 6 ga wire) directly to the plug. As well as any purely electrical reason, I also think it would avoid likely interference problems with a bow mounted sonar unit.