Battery Won't Charge While Engine Runs
I have an 84 Wellcraft 200 elite w/a 260HP merc. Symptoms are as
follows:
- Battery never charges while under way after a day on water. Has died
sometimes but I take a spare. Still, no fun.
- Dash voltmeter never reads more than 11V --usually less. I recharge
bttys before each trip. 11V or less even w/new battery.
- Have to retighten alternator belt often. Rubber dust on engine hood
says it's getting ground down. Running out of room on adjustable bar
for Alt.Here's what I've done so far:
- Brand new marine battery, new Alt and Starter last year.
- Brush corrosion from posts, cables, wires. While idling, Alt reads 40A on back w/ multimeter. No juice getting to
btty, tho. Someone said maybe Alt pulley is wrong size (tho I gave old
one to match at Alt shop). Said maybe a '9 series' pulley to match belt
#9440. Alt shop guy never heard of it tho. How crucial is belt brand?
Have matched size of new one from auto parts store to old one. Any ideas much appreciated! THANKS. -- STB |
riverflow100
Aug 1
2006
|
| As another poster mentioned, you must put the meter in series with the
alternator and load when measuring current. If you truly read 40A (which you didn't), something had to be PULLING
that much current. The only thing on your boat that would pull that kind
of current, other than a serious short, would be the starter motor. |
Mark
Aug 2
|
| On 1 Aug 2006 11:09:45 -0700, riverflow100@yahoo.com penned the |
Gene
Aug 2
|
| On 1 Aug 2006 11:02:49 -0700, Tim penned the following well considered
thoughts to the readers of rec.boats: >Gene, Mando sounds correct for marine use. Many OE's use Mando (korean
>motorola) ..... ??? Where did "Mando" come from? Did I miss part of this thread?
|
Gene
Aug 2
|
| Try a brand new marine belt of the correct dimensions. You probably won't
find one in an auto parts store.
Check belt alignment.
Check for rust on pulley belt surfaces.
Check to see if the fuse between battery and alternator is good.
Keep belt tight at all times. Make it part of your pre-op checks. |
Jim
Aug 1
|
| Also, be damn sure not to *over tighten* the belt. This has caused me some
expensive repairs.
-- ***** Have a Spectacular Day! ***** John |
JohnH
Aug 1
|
| check and see if you hav4e power at your output terminal (the wire that
goes to the back of the alternator) dual batteries? it's possible that
you have a bad battery isolator (the little aluminum thing with the
fins on it that the battery cables from
the alternator hook to) A bad engine ground, can cause the alternator to pull hard, and thusly
eat a belt. Can you tell me/us what engine set up you have, and what alternator you
have on it? Delco? prestolite? Motorola? Mando? It helps to know these things.
riverflow100@yahoo.com wrote: |
Tim
Aug 1
|
| Plus! If yiour alternator has a bad diod[s] and/or a defective stator
winding, the alternator will charge insufficiently and cause a hard
drag on the belt. riverflow100@yahoo.com wrote: |
Tim
Aug 1
|
| Thanks for replies.
Don't know about bad diode/ stator winding, Tim. Will take Alt to shop
to bench test.
Engine is Mercruiser MCM260. S/N is 6678458. Alt says Arco #60109
(marine SAE J1171)
Also says made by Mando on back. 55A. At idle it was putting out 40A which Alternator shop guy said was
normal I do have rust on main pulley, not on Alt tho. There's one culprit... ....couple questions from the Stupid ? Dept. |
riverflow100
Aug 1
|
| The lack of charging says probably a bad connection to the battery from
Alternator. Either ground or hot line. The pulley eating belt is probably
a pitted pulley, change the pulley for a new one. Been there, done that on
a pulley. |
Calif
Aug 1
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| On 1 Aug 2006 07:49:09 -0700, riverflow100@yahoo.com penned the |
Gene
Aug 1
|
| The fuse is easy. Look for about a 1 in" square thing attached to the same
post on the starter that the + battery cable is attached to. Attached to the
square thing is a wire that goes to the alternator. The square thing is a
fuse. Check it with an ohmmeter.
The main engine ground is a stud on the back of one of the heads. There will
be a battery cable attached, and maybe some other grounds. To check engine
ground, set your voltmeter to 2 volt DC scale. Attach black lead to battery
negative. Attach red lead to a good bare metal spot on the engine block.
Read the meter while the engine is cranking over. Anything over .2 volts
means a bad connection somewhere.
Jim |
Jim
Aug 1
|
| Gene, Mando sounds correct for marine use. Many OE's use Mando (korean
motorola) for a charging unit. And there are several models of
Mando's. Unlike most old generators, and alternator is bi-directional,
and doesn't care which way it turns to make current. Mando units are ,
well, CAN be kind of finicky tow work with and are expensive. I've
canned a few of them and showed my suctomers how to convert over to a
marinized , Delco 10-SI unit. It's cheap, easy and reasonably
reliable. But even so, a reputable auto parts store "should" (notice: I said
"should?)be able to test the Mando unit. BUT I'd still take it to a
reputable Starter/alt. shop. Gene Kearns wrote: |
Tim
Aug 1
|
| Thanks for replies.
Gene - Alt (marine SAE J1171) says Arco #60109. Also says made by Mando
on back. 55A.
Will get a Merc belt tho have been told not crucial.
Re: mutimeter question -- not a clip-on. Probe style. Jim - Thnx for fuse and ground info. |
riverflow100
Aug 1
|
| 84 you probably have all sorts of bad connections due to corrosion.
Start at the battery, after charging it, with your voltmeter and then
move down the line to see how much the voltage drops at various places. riverflow100@yahoo.com wrote: |
jamesgangnc
Aug 1
|
| You got to get back to basic checks first:
1-what's the voltage on the alt post?
2-40a, if it's an inductive ammeter and it's placed to close to the alt, the
magnetic field present may confuse your reading.
3-do a voltage drop test on your alt (+) wire and (-)wire on the block.
4- good voltage should be around the 14v +/- .4v <riverflow100@yahoo.com> wrote in message |
Lost
Aug 1
|
| Have you checked the wiring from the alt to the batt? I had a crack in
that wire in my car and it had same symptoms (new batt, new alt, no
charge). |
Alotta
Aug 1
|
