Battery short?

[BigSplash]

So, I finished winterizing my Suzuki df 140, which drives my 26' pontoon. It is equipped with two 12 volt batteries. Sadly, I unhooked the first battery taking off the positive lead first...by the time I removed the ground lead I discovered two wires, very near the bottom on the lower unit, smoking. I think I just shorted something and burned off the insulation...any thoughts on what, if anything I may have damaged? Thanks!

 

[99yam40]

Re: Battery short?

I do not see how disconnecting the pos cable 1st would short anything.
Usually the neg is disconnected 1st just so you don't accidentally short across things(to ground) with the wrench while undoing the pos cable.

Did you have some other things turned on or try to start motor with some of the cables off?

Some thing was drawing current to heat up those bonding wires which are not there to carry 12 v power, they are for bonding the parts of the motor together so that the sacrificial anodes can protect them.
If you disconnected one neg cable from the motor or the house battery neg to the boat and had
something turned on then it could have tried to get back to the battery any way it could and that may have been through the bonding wires.
Just trying to think of ways to make this happen and it is hard to do as you have not given much to go on.

With 2 batteries it can get complicated without knowing how everything was hooked up.

 

[CaptainKickback]

Re: Battery short?

How are your two batteries wired? Through a battery switch (1, 2, or both)? What was the switch set to when you pulled the cable? Did the loose positive cable touch anything before you got the neg off?

 

[BigSplash]

Re: Battery short?

Hey Kickback & 99yam40...I think you are both onto the issue. The battery selector switch was set to have both batteries truned on and I think probably after I unhooked the pos cable I just let it dangle and no doubt it contacted the hull...and then the "bonding wire" is what started to smoke. I have talked to a few other folks and emerging consensus is likely no major damage...at this point I'm thinking to leave sleeping dogs lie until spring! Of course, if I getr a warm day I may drag the batteries back out from under the porch and hook 'em up! Thanks!