Positive Battery Terminal Getting Hot...

reeldreamer

Cadet
Joined
Nov 20, 2011
Messages
16
I haven't started my boat in a few months and tried to today... On the first 5 or so cranks it seemed to crank well but didn't start, after those 5 or so cranks it began to slowly die off and got slower and slower as if the battery was getting weaker... It was fully charged. Anyways, I checked the battery and the positive terminal got very hot.

Could this be the starter or in need of a new positive cable? I just stopped trying to start it once I realized the battery got hot and because it was having a hard time cranking over, it seemed sluggish.

I may try to post a video on exactly whats happening so you guys can get a better understanding of the situation..

BTW its a 1984 Merc Blackmax 150hp Outboard

Thanks,

-Christian
 

bruceb58

Supreme Mariner
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Mar 5, 2006
Messages
30,454
Re: Positive Battery Terminal Getting Hot...

Remove and clean your battery terminals, reinstall, charge your battery and try again.
 

MH Hawker

Vice Admiral
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Jul 13, 2011
Messages
5,516
Re: Positive Battery Terminal Getting Hot...

Yes you have a bad connection.
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,657
Re: Positive Battery Terminal Getting Hot...

And yes, the cable itself could be corroded under the insulation.

You could try using a jumper cable, and connecting directly from battery to the starter.
 

joed

Lieutenant Junior Grade
Joined
Sep 28, 2002
Messages
1,132
Re: Positive Battery Terminal Getting Hot...

Heat in any electrical connection is a result of a poor connection. Same thing will happen with wiring in your home if you have a loose connection. High current draw will expose the problem quickly.
 

reeldreamer

Cadet
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Nov 20, 2011
Messages
16
Re: Positive Battery Terminal Getting Hot...

I'll try replacing the cable 1st and let you all know if it works or not...

thanks
 

little.boat

Seaman
Joined
Mar 25, 2013
Messages
73
Re: Positive Battery Terminal Getting Hot...

Sounds like bad connection. Try cleaning as stated above and when you put the nut on the terminal post really crank it down, using a wrench or pliers. Sometimes you can finger tighten them, other times finger tightening causes your exact problem.
 

Bondo

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Apr 17, 2002
Messages
70,468
Re: Positive Battery Terminal Getting Hot...

I'll try replacing the cable 1st and let you all know if it works or not...

thanks

Ayuh,.... Just Clean the battery connectors to shiny clean metal, 'n try it 1st,...

Heat = Resistance = dirty connections,....
 

reeldreamer

Cadet
Joined
Nov 20, 2011
Messages
16
Re: Positive Battery Terminal Getting Hot...

I still have yet to do anything (been busy). I didn't mention it in the post above that I did try it on 3 different batteries... so I know the battery terminals aren't the issue but will check the connections by the starter, clean the cables, and if that doesn't work I'll buy a new cable.

Thanks again

-Christian
 

Bondo

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70,468
Re: Positive Battery Terminal Getting Hot...

I still have yet to do anything (been busy). I didn't mention it in the post above that I did try it on 3 different batteries... so I know the battery terminals aren't the issue but will check the connections by the starter, clean the cables, and if that doesn't work I'll buy a new cable.

Thanks again

-Christian

Ayuh,.... Changin' batteries does Not necessarily equate to Cleanin' the terminals,....

sandpaper both the post, 'n the cable ends,....
 

boobie

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Messages
20,826
Re: Positive Battery Terminal Getting Hot...

Are you in a salt water area ??
 

joed

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Messages
1,132
Re: Positive Battery Terminal Getting Hot...

If the terminal at the battery is getting hot then the issue is with that terminal not the starter connection. If the starter connection was a problem then the starter connector would be getting hot. It could be the cable to clamp connection and not the clamp to battery connection that is the problem.
 

reeldreamer

Cadet
Joined
Nov 20, 2011
Messages
16
Re: Positive Battery Terminal Getting Hot...

Gotcha, I cleaned all connections and bought a new battery cable.... this time after trying to start it the cables got barely warm and the starter wouldn't crank over. You could see it trying to engage but it wouldn't crank (the batteries were charged). Would that be a sign of a new starter or solenoid?

Thanks,

-Christian
 

alldodge

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40,582
Re: Positive Battery Terminal Getting Hot...

Gotcha, I cleaned all connections and bought a new battery cable.... this time after trying to start it the cables got barely warm and the starter wouldn't crank over. You could see it trying to engage but it wouldn't crank (the batteries were charged). Would that be a sign of a new starter or solenoid?

Thanks,

-Christian

Think now you have a real bad connection (barely warm and will not crank) or your starter windings burned.
 

bruceb58

Supreme Mariner
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Mar 5, 2006
Messages
30,454
Re: Positive Battery Terminal Getting Hot...

Are you checking the ground cable as well?
 

erie_guy

Petty Officer 1st Class
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Jan 16, 2007
Messages
269
Re: Positive Battery Terminal Getting Hot...

You might want to measure terminal voltage on the battery, especially while it is trying to crank the engine. Get a digital multimeter from Harbor Freight ($4) and check to verify you have 12.6 volts before you press the start button. During cranking, the battery voltage should remain above 10 volts. If it falls below 10 volts, you can get excessive heating, and the battery is probably shot. You can also check your battery with a hygrometer to verify if the battery has accepted a full charge. I believe the acid should show 1.260 gravity if it is fully charged.

Also check your battery terminal voltage while the charger is working on the battery. I would anticipate seeing a 14.4 volt reading if the charger is working well.

Best of luck in finding the problem.

erie_guy
 

joed

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Messages
1,132
Re: Positive Battery Terminal Getting Hot...

Measure the voltage at the starter terminal while it is trying to crank. If that is no good then measure at the battery post and then the cable terminal.
 

sam am I

Commander
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Jun 26, 2013
Messages
2,169
Re: Positive Battery Terminal Getting Hot...

Hold still you Screwy Wabbit!!! Sounds like one of those morphing types :facepalm:...

Given the cables all appear ok now......Guess what I'd do at this point (with the appropriate PPE), is connect a voltmeter across the starter.....ON the stater's "+" and "-" power cable studs!!! and IF motor turns easy'ish by hand

Hit the key, 12V'ish on those studs and no turning = motor bad (open winding's/brushes etc)...problem found

Else solenoid is bad or shorted motor....... I personally carefully test by jumpering them with screw driver shank(it's a personal touch....lol), watch voltmeter again(not too necessary),

Excessive BIG arch and low/er voltage and no spin = motor bad (shorted winding's/armature to ground etc)....problem found

else the thing spins up fine and the solenoid had just gone to crap...problem found


Outboard_starter_Page_1.jpgOutboard_starter_Page_2.jpgOutboard_starter_Page_3.jpg
 
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