Altenator lead wires

jam1ej20

Petty Officer 2nd Class
Joined
Mar 31, 2009
Messages
111
I have a 95 mercruiser 4.3LX and my question is about the lead wires to the altenator, specifically the lead wire to the ground post. Is this lead wire a fuseable link type wire? Or is just a standard piece of wire? Turns out that they will FRY if power is supplied to the ground wire...who knew :rolleyes:
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,321
Re: Altenator lead wires

the ground wire is just a piece of primary wire... nothing to special.
But if you miss-wired your alternator you can bet you fried it. Specificly the voltage regulator in it.
 

jam1ej20

Petty Officer 2nd Class
Joined
Mar 31, 2009
Messages
111
Re: Altenator lead wires

Actually, only the wire fried; that's why i was asking. I pieced in some normal wire for a temp job to get it running and everything checks out ok. Got lucky, i guess. The motor is out of the boat so I crossed wires by mistake while attempting to supply power to make it run. The lead wires are listed as NLA from merc. but no info is readily available as to what, if anything, was special about them...other than color coding.
 

boat1010

Senior Chief Petty Officer
Joined
Mar 10, 2009
Messages
781
Re: Altenator lead wires

When you say the wire "FRIED" are you actually saying it burnt in two, or just got hot and melt the wire coating? Just wondering...
 

jam1ej20

Petty Officer 2nd Class
Joined
Mar 31, 2009
Messages
111
Re: Altenator lead wires

It actually burned into two pieces. As soon as I connected the battery, white smoke, a little sizzle, and before I could disconnect the battery, the wire was already burned through. It really seemed more like a fuseable link, maybe as a safety design for the alt. If not, why have the lead wires drawn separately on the schematics and short lead wires instead of just connecting directly to the alt? Anyway, just wondering.
 

abj87

Petty Officer 1st Class
Joined
Aug 4, 2008
Messages
354
Re: Altenator lead wires

Why would they put a fusible link on a ground wire? theres no point. Just watch how you wire it up next time ;)
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,321
Re: Altenator lead wires

hooked the battery up backwards didn't ya :)
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,344
Re: Altenator lead wires

Nobody`s ever going to admit to that,takes a lot to burn thru a #6 or #10 wire. If you did accidently do this, remove the alt and have it checked. I`m sure it suffered some damage
 

jam1ej20

Petty Officer 2nd Class
Joined
Mar 31, 2009
Messages
111
Re: Altenator lead wires

As stated above, alt. is good. They are lead wires and there's really not a lot of difference between "purple" and "black" on a 95 motor with normal grime and dirt build up. Honest mistake. Just switched up the connections and supplied 12V directly to ground. It didn't run this way, just hooked up the batt and the wire immediately smoked out and burned into two pieces. I guess my question is, if they aren't fuseable links, then why have lead wires at all? Just hook the wire directly to the alt. and not worry about a connection 3 inches from the alt.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Altenator lead wires

I guess my question is, if they aren't fuseable links, then why have lead wires at all? Just hook the wire directly to the alt. and not worry about a connection 3 inches from the alt.

Because that's how Mercruiser made them. They don't give reasons for why they do anything to their dealers, let alone tell the individule customers.
Does your car dealer explain why they use the wire they do? I doubt it.
It's not a fusable link. I'm afraid you are goiing to have to live with that or call Mercruiser engineering and hope for an answer.
 
Top