[257scramjet]

So i pulled my boat out this year and hooked up a fresh battery. I cranked over the motor for about 30 seconds and the positive battery cable melted at the terminal!!! WTF could this be? i have never had a problem like this before. The Negative cable was pretty hot as well but did not melt. I am not an electrician at all! Where do i start? Maybe the starter melted down and caused this? The only thing i have changed on this boat was an alternator last year.. We changed it to a higher amp alt. but it ran fine for 2 trips last season? Any and all help would be greatly appreciated.

Thanks,
CB

 

[Buoy]

Possibility that the connection was loose, causing it to arc from the terminal to the cable clamp?
I'm not an electrician either, but I've heard of this before.

 

[Oldelmn8tr]

Check for a short on the pos. cable to starter, also to alternator. Make sure all ground connections are clean and tight. Did it crank slow at any point? Have seen bad starter pull a ton of amperage and cause this also. Let us know what you find.

 

[GT Jets]

Running the starter motor for "30 seconds" is never recommended, that is an eternity...Like was said the connection where the heat occured was more than likely loose...

GT hand

 

[257scramjet]

Check for a short on the pos. cable to starter, also to alternator. Make sure all ground connections are clean and tight. Did it crank slow at any point? Have seen bad starter pull a ton of amperage and cause this also. Let us know what you find.

Yes it did crank slow right before it melted. The problem i was having was the motor was not firing up right away. What was really wierd is i would hit the key and it would crank for awhile, once i let off the key it would hit or try and run??? I noticed this last year when we installed the new higher output alternator. As a matter of fact i remember when i first installed it, i fired up the motor and it would not shut off.. We installed a diode or something inline and the problem went away... ANY IDEAS? I will replace battery cables on saturday and see what else i can find..coffee

 

[Guest]

Loose or bad connection.

Make sure you clean the terminal & connector with scotch brite and then put a little grease on it before you torque it. Doesn't take much heat to melt lead, a few hundred amps while cranking with a bad connection will do the trick.

 

[1975sleekcraft]

starter

if you ran the battery down, in some cases the starter will stay engaged and not be turning anything over. thats when i have seen cables smokin!!
other than that, sounds like a dead short!! need to isolate it!!

 

[257scramjet]

if you ran the battery down, in some cases the starter will stay engaged and not be turning anything over. thats when i have seen cables smokin!!
other than that, sounds like a dead short!! need to isolate it!!

OK how would i go about finding a dead short/ isolating it? What tools do i need? Sorry, i'm completely Electrically challenged... My thought is it's either got to be in the starter or the alternator? So i guess i'll start there?

 

[SS 201]

Be sure you have the right cable, right length.

 

[Homez]

OK how would i go about finding a dead short/ isolating it? What tools do i need? Sorry, i'm completely Electrically challenged... My thought is it's either got to be in the starter or the alternator? So i guess i'll start there?

Put the battery on a slow charge then check/clean up your cables and connections to the posts-if it was fine when you put it away and thats the only thing you messed with thats the problem I'm guessing

 

[Outlaw]

Yes it did crank slow right before it melted. The problem i was having was the motor was not firing up right away. What was really wierd is i would hit the key and it would crank for awhile, once i let off the key it would hit or try and run??? I noticed this last year when we installed the new higher output alternator. As a matter of fact i remember when i first installed it, i fired up the motor and it would not shut off.. We installed a diode or something inline and the problem went away... ANY IDEAS? I will replace battery cables on saturday and see what else i can find..coffee

check your key switch, when you let off the key it fires up.
I've seen this before, bad switch. as for the cable, loose connection
IMO

 

[stix818]

X 2 on bad or loose connection (most likely)!!! You need a meter to check for a short, if you want to know more PM me and I'll give you a hand.. Check some of the items they listed above.

 

[SS 201]

Put a volt meter across the battery and turn over the starter, check the starter draw. Should be no more than 2 volts, if more the starter has too much draw.
Be sure battery is full charge so as not to get a false reading If more you have a starter is bad, likely the bushing is bad and the armature is draging.

 

[ap67et10]

you do NOT have a short. A short means that the B+ is somehow touching ground before the switch or load. if this were the case with your boat, it would have created a massive spark and instant smoke on the neg. terminal when you first attached it to the battery (because you do disconnect the battery every winter right?? and pos. goes on first neg last) so this would have been immediately smoked if you had a short as there is constant B+ present at the starter. what you have is a high current draw when cranking and your cables were the weak link. however like GT said 30 sec. of cranking is a long time, but still your system should be set up to crank as long as your battery has juice.

Questions: do you have an MSD box on this boat? did you have to wire your new alt. differently than your last one? if so what did you change?

its possible the switch is bad making it not lite off till you let off the key, but the majority of the time I have seen this problem its because its incorrectly wired and the ignition ends up not getting B+ when in crank position.

AP

 

[257scramjet]

Thanks for the answering my questions, I replaced the positive cable with a new unit, replaced the ignition switch, re wired a few connectors that looked not good, and now she fires up on the first bump of the keydevil
Thanks for all the advice!