Trolling Motor Fuse Block

[YoMoma]

I`ve recently purchased a used Bass tracker boat and first time out I had trouble with the tracker trolling motor. It is a Tracker 40. With 43 lbs of thrust. Stock 2001 motor.
I took the boat out on a trolling motor only lake. The motor worked great for nearly an hour. Then the trolling motor seemed to stop totally.Took an hour for it to work again, only for it to quit 2 minutes later.
I have 6 guage wire up to about 1 foot from the battery. It looks like 12 gauge from there. The previous owner put a 40 amp fuse in the fuse block. It pretty much began to melt the fuse block, part of the outter coating of the wire an inch away nearly melted off the wire.
My question is, what guage wire needs to be there with the fuse block and what amp fuse would be sufficient? Or do I have a grounding problem?
It is a 12 volt system.

 

[joeanna]

https://www.bluesea.com/resources/1437 has a chart for the minimal size of wire recommended,, the smaller size and or length will in effect, be a current limiting resistor in your circuit, and may get warm or hot....just like a bad rusty connection will do the same, I like to go on the safer side with a larger gauge wire if I can, especially if long length becomes an issue,

 

[YoMoma]

Manual says 12 volt models need a 50 amp circuit breaker in line. I found this one, but is this overkill? That's the only mention I see in the manual that alludes to haw many amps it runs on.
https://www.trollingmotors.net/products/motorguide-50-amp-breaker-with-cable

 

[gm280]

If you have a 40 amp fuse and it stopped, and then started again only to stop the second time, the fuse wasn't the problem. Fuses only blow one time and then has to be replaced. So unless you have a circuit breaker that auto resets itself, you still haven't found your problem. I will say it sounds like a heat issue, but not being there and testing things myself, that is merely a wild guess. I would run at least 6 gauge wire, but all the way from the battery to the trolling motor and NOT change wire sizes. I thinking the problem is in the connections at either the battery and/or the wire size change over. I would start there first. JMHO

 

[YoMoma]

Well took a voltmeter to the system. Put a new 12 guage wire and 30 amp fuse. Similar to what was there before. We have power at the fuse block, but nothing at the trolling motor connection at the front of the boat.

 

[Silvertip]

You cannot use 12 gauge wire anywhere in that system. A 40# motor draws somewhere in the vicinity of 40 amps at full load which is why a 50A breaker is specified. 12 gauge wire is rated for only 30 amps. 10 gauge would even be marginal. That may not solve your problem with the motor but it is what the wiring needs to be for safe operation.