Trolling motor cables heating up

[mixxedbagg]

I have a 30lb Minnkota trolling motor that I purchased several years ago but haven't used much. I put it on my boat last night and every time I ran it, the cables (especially the positive) would heat up, mostly right next to the terminal clamps. After about a minute of running at '5' or a few minutes of running at '1 or 2', the cables would get hot enough to make the insulation smoke. I tried a couple of different sizes of deep cycle batteries with the same result. Does anyone know how I can prevent this??

[DrKen]

It's not the battery that is the problem but the trolling motor. Your cables should not be heating up like that. 2 possibilities. First would be the cables being either undersized or having a short in them. Second, is that the motor is going bad. It is drawing far more amperage to run than it is designed to. Beg, borrow or steal a clamp on ammeter and see what the motor is drawing and that will tell you more. There should be a plate on the motor stating max amp draw by the motor and if the ammeter shows you drawing more than that then it's on it's way out. Hope this helps

[Surface Tension]

Dr Ken has some good suggestions. I would add that since the heat is developing next to the clamp it could be as simple as bad connection. Clean both battery posts, when you go to clamp, rotate the clamp as it bites into the post. What condition are the clamps in? Are the springs still strong, and is the cable to clamp connection good? Pull the plastic sheath off the clamp and have a look.

[mixxedbagg]

When I look closer, the cable to clamp connection may be an issue. There is a burn hole in the insulation directly above that point. I'll redo it and see what happens.

[solbes]

I would also guess it's the connection as you said. My Autopilot kept turning off when our boat was brand new. The dealer had a poor motor to plug connection that also got hot. I re-did the connection and problem solved.

[Ed Carlson]

Poor connections will heat up the wire preaty quickly and drain a battery prematurely. Re-do the connections and clip off some of the old wire if it looks fried or corroded. If new wire is needed run as heavy a gauge wire as you can, 8 gauge should do it well.

I also recommend coating the connections with a product called liquid electrical tape, it's paint on and shrinks tight to protect connections from oxidation and corrosion...good stuff on all things marine and electrical.

[mixxedbagg]

Well, I redid the connection, but it's still getting hot--fast. The clamps are good, I made sure they bit into the terminals, and the cables are the ones that originally came on the motor and seems fairly stout. I bought it new and it hasn't been used much, so it would be a surprise if it were drawing too much on its own. Maybe I'm doing an inadequate job with the connection, but it looks pretty self explanatory...wire + clamp.

[Surface Tension]

Did you cut the wire back and solder clean wire to a clean clamp? Clamps are quick and easy but not the best type connection especially with electric motors that draw a lot of amps. I tin my ends, make a loop, then a direct connect to the battery.

If your sure about the good and clean connections then I'd do as Ken said and check the amp draw. Or bring it into an authorized Minnkota repair center.

I wouldn't use this till you get it fixed.