Hey all. I have a 55 thrust Minnkota and today the battery terminals got fire hot. Any clues as to why that happened?It never happened with my 4o thrust. All are 12 volt. Thaks for any thoughts sent my way.

Sounds like you got a short somewhere. Is there boat wiring involved or are you connecting the troller directly to the battery? I'd check every inch of the positive wire from the battery to the troller motor and find out where it's grounding out.

I connect directly to the battery. Could there be a short on the trolling motor somewhere?

That would be more likely than a short in the battery, although batteries can short out as well. Can you test the troller on another battery? Or take the battery to your local auto parts store (like NAPA) and get it tested. It's either one or the other.

Ben is the guy to ask, I'm sure he will have an educated answer for ya..

If you have a switch that sets the 12 or 24 volt and it is flipped the wrong way that will happen.  I almost burned my boat to ash the first time I took my wife out.

J

You say all are 12 volt so I take it this motor is a 12V only motor and not a 12/24.  Was you running on max or just easing around when you noticed it hot?  How are you connecting to the battery, aligator clips or eyelet terminals.  Bad/loose connections will cause one to heat up enough to melt the insulation on the wires and draw a blister when you touch it.  For that large of a motor, you should have eyelets and make sure they are well crimped, bad crimps will cause the ends to heat up enough to melt,  the terminal ends are clean, the battery terminals are clean and the nuts holding them are good and tight.   Is this the TM cable connected directly to the battery or is there other cable between the TM and the battery?  If so, what size is it, it could be too small.

Are you running circuit breakers?  could be the wrong size and bad.  I've seen those things melt and not trip.  

Bad, dirty, loose connections would be the first thing I would check because they are the main causes of over heating cables/terminals.  THis can be checked with a DVM on a low voltage setting  buy placeing one test lead on the battery post and one on the copper wire, (not the terminal).  Check both negative and positive cables.  If you measure any voltage, you have a bad connection and need to repair/clean it.

Hey Ben.

It is a 12v only and I was running on full alot that day. I am connecting directly to the battery from the TM with eyelets to the screw terminals with wingnuts. The connections were good. The terminals are clean. No circuit breakers...are they necessary? I will check to see if the eyelets are well crimped.

So with the DVM, I hook up the motor as usual and set one test lead on the pos post and then a piece of the connecting wire above the eyelet connector somewhere? If I get a reading, I have a bad eyelet connection?

THANKS!

That's correct, but do it with the motor under a load, running in water on max.  Circuit breaker protect things from going up in a blaze of glory if something shorts out.  Not totally necessary but a nice little precaution, on that much motor and it only being 12V, be sure you go with at least a 50 amp