Lazy alternator

Lift12

Seaman Apprentice
Joined
Oct 30, 2018
Messages
38
1998 7.4 MPI 0L347054
Alternator doesn't start charging till RPM gets above 2500 but will continue charging at lower revs once it starts. Is it just time for a rebuild or is there something else at play here?
 

matt167

Rear Admiral
Joined
Sep 27, 2012
Messages
4,151
That means it’s not getting power to the exite wire and needs to exite itself. Check for broken wires.. if the boat is new to you someone might have wired it as a 1 wire alt which works like that
 

zellerj

Petty Officer 2nd Class
Joined
Dec 13, 2017
Messages
136
Sometimes with winter condensation etc, corrosion limits the alternator's function. Try spraying some WD40 into the unit to polish it up some. Worked for me when I had this issue.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
49,570
Pull the alternator, put a new regulator in it
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,958
1998 7.4 MPI 0L347054
Alternator doesn't start charging till RPM gets above 2500 but will continue charging at lower revs once it starts. Is it just time for a rebuild or is there something else at play here?
Ayuh,..... It should kick in at 'bout 1500 rpms, 'n run continuous after once rev'd,........
 
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