Incorrectly installed battery

ODD

Cadet
Joined
Mar 29, 2006
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6
I have a 2004 Merc 50 hp 2 stroke. Due to my negligence I had incorrectly hooked the negative to the positive cable to my battery. After about 20 seconds I saw smoke coming from under the cowling and coming from the throttle, promptly unhooked the cable. The fuse(20A) keeps blowing whenever I try to start it. Everything else seems fine, tilt works. Besides my stupidity which I hope you'll refrain from chastising me, how much damage did I cause, and more importantly, how much $$$!
 

Texasmark

Supreme Mariner
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Dec 20, 2005
Messages
14,780
Re: Incorrectly installed battery

Alternators, which engines of today use to charge your battery, usually use a 3 phase full wave bridge rectified circuit. That's 3 diodes for the positive output......to the battery + and 3 diodes of reverse polarity to ground which connects to the batt - terminal.<br /><br />Iffins you reverse the polarity of the batt or a charger, you put +12v on a diode (to ground...chassis...motor metal) with no resistance to limit the current. It immediately fries and fry is in the short condition and that means smoke.<br /><br />Sorry, but that's the way it is and I bet you don't make that mistake again.<br /><br />Mark.
 

ODD

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Mar 29, 2006
Messages
6
Re: Incorrectly installed battery

Let me correct myself, I believe I hooked the leads to the throttle assembly, not the leads to the motor, that could explain the smoke coming from the throttle assembly. Are you saying I need a new alternator?
 

WillyBWright

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Dec 29, 2003
Messages
8,200
Re: Incorrectly installed battery

You need a new voltage regulator on the motor. I believe you also got smoke at the remote control? That's odd. There's a warning horn in there that could do that I suppose. Or the wiring melted and you'll need a new harness.<br /><br />Don't feel bad. Electricians do it too (Black isn't Hot). ;)
 

ODD

Cadet
Joined
Mar 29, 2006
Messages
6
Re: Incorrectly installed battery

As you can tell I know very little about outboards. What exactly does a voltage reg do? Is this easily repaired by a pro? Any other damage I might have caused?
 

MercFan

Petty Officer 1st Class
Joined
Dec 31, 2005
Messages
347
Re: Incorrectly installed battery

Sorry, but like most electric stuff, it's sealed. You'll havta buy new things. New regulator, new "whatever smoked in the control". Check your wiring harnass for bubbled insulation. Prolly havta buy that new aswell... :-/
 

WillyBWright

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Re: Incorrectly installed battery

You can easily change it yourself. It'll have 2 yellow wires and a red, maybe a black and a gray. The alternator puts out AC voltage that varies with engine RPMs. Voltage regulators bleed-off excess voltage and change AC to DC.<br /><br />The blowing fuses problem is the one I'm most concerned about. That and the smoke at the throttle make me think you melted some wiring. I've also seen shift/throttle cables melted from incorrect battery connections once or twice. Most of the time the regulator is the only casualty. Gotta find what made the smoke at the remote control.
 

ODD

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Joined
Mar 29, 2006
Messages
6
Re: Incorrectly installed battery

Yeah I do think I melted something in the throttle. If I did melt some wiring, your talking wiring from the throttle to the motor, not within the motor?
 

WillyBWright

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Re: Incorrectly installed battery

Wiring under the hood may have been affected too.
 

ODD

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Mar 29, 2006
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Re: Incorrectly installed battery

Could there be some possible long term damage? BTW, thanks for the help everyone.
 
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