Alternator pully question.... did I hurt it??
 

It's almost time to yank my motor out to see what damage I did. One thought came to mind the other day. When I put this thing together last spring, I put a new high output one wire alternator on. Well, the only belt I had did not fit with the pully that came with the alternator, I was leaving for LOTO the next day (no sea trial, just dropping it in, starting it up, and taking off!). So, we took the smaller pully off my old alternator (which is non-functional) so the belt would fit (it was late, no place open to get a new belt). Everything seemed to be fine, so I never replaced the pully or the belt.

Long story short, my issues seemed to have started with an electrical problem, one battery seems to have shorted out, ignition shut off, motor quit, swell came over the transom, motor got hydrolocked, rod got bent, etc... Could the smaller pully spinning the alternator faster have done any damage to my electrical system???

'Foul

Sounds like a bad regulator.
Overspeed "shouldnt" have killed it but you never know.

Re: Alternator pully question.... did I hurt it??
 

Unlikely:rolleyes:
You should be able to have it tested at a number of different places.

What I'm wondering, is did the alternator, by spinning faster, do any damage to my system? The volt meter on the dash usually read 14 or so, but that day it would not go over 12.5 with the battery switch on "both." Could a DEAD or shorted out battery cause the alternator to get hot? The paint on the housing pretty much burned off that day. When the motor quit, I opened the hatch and the alternator was smoking, and too hot to touch.

ttt

sounds like the alt was trying to charge a bad battery
or you had a short. I used to rebuilt starters and Alternators long time ago :)
the smaller pully should not have made much diff
I have had to replace many Alt in peoples cars at my buddy auto shop people will not replace there battery
they want to see if they can get 7 years out of them
and it ends up costing more money.
I would think you just had a freak short in the cell

I was told to never run the bat switch on BOTH on a single engine.
I have twins and never run mine on both would hate to burn anything up.
I would be checking you regulator, or maybe the alt itself was not right to begin with. Sucks
Batteries are replaced ever 2-3 years. Period.
Gues that is learned from teh frigid winters in MN
First sign of weakness, GONE would rather spend a hundred on a battery then one freezing day with a dead one. But as for boats, I also replace tehm every two years. They take alot of abuse and I look at it as preventive maintenance. Especially if they sit more then they are used :(

The regulator doesnt care how fast you spin the alt., as long as it's working right. Look at the volt meter in a car-at idle, around 12 volts or so. So spin it up a little off idle and it comes up to 13.8 14 or so. Rev higher, no difference. That's it's job.
I'd check the alt. if it got that hot. All that load might have tossed it if 1 batt was bad. As far as running on BOTH, if the alternator is rated high enough to charge both at the same time, no foul. ;)
At the same time, 1 batt being trashed(shorted cell) WOULD cause you to see low voltage at the gauge as the bad batt. could load down the alt. AND the good batt at the same time.
So in your scenario---how long had you run the boat before the ignition dying? Was your voltmeter still showing DC voltage after it died?
So no I don't think the pulley did it. Yes maybe running on Both switch MAY have caused alternator failure. Need answers to my questions above to opine further. Definitely get batteries and alternator checked out before trying to run it again.

$.0001

Why would running on BOTH smoke the alternator?
It just swaps between a single battery load and a dual battery load. I don't see a problem there. (I always cruise on BOTH, and only swap to a single batt when anchored). On a single I see no problem. On a twin, you got a little "fighting" of the two regulators, but you'll just end up with one alt being satisfied before the other which is no biggie either.

If a battery was shorted, then that usually just means one or several cells are shorted and the remaining cells are forced to take an overcharge which munches the battery...

If there is a short in the WIRING, then that definitely could have sent the alternator to heaven if run long enough.

As far as smoking regulators with fast alternators - a buddy of mine fought blown regulators right and left on a 7300 rpm big block Dodge. It was fine until he made a full-on pass then it was toast. He probably went thru ten regulators playing with it on the street (he'd take the alt belt off at the strip). We put a toggle switch on the field wire of the alt and he never had anymore problems (as long as he switched it off before redlining it). Can I figure out exactly WHY this kept blowing the regulator? Nope. Makes no practical sense to me. But it certainly DID. Over and over. (His regulator was external to the alternator).

"If a battery was shorted, then that usually just means one or several cells are shorted and the remaining cells are forced to take an overcharge which munches the battery..."

Never seen a battery blow up? I have, several.

Oh, sure, I've seen several as well.
One right in a dum@ss service manager's face when he hooked a plugged in 150 amp quickcharger to the battery he was hunched over the top of. Good thing there was a garden hose nearby or he wouldn't have made it out of there with any skin on his face.

I am talking about how it affects the ALTERNATOR. Foul didn't blow up a battery - he smoked an alternator. An alternator is designed to charge at full rate amps for a pretty good length of time without overheating, and his baked the paint right off it.

I had one brandy new Optima blue top and one several season old 1000 cca battery I got when I worked at Boat US (don't remember the brand at the moment). But, with the switch on BOTH that day, I got about 12.5 or so at WOT, and less than 12 at idle. Switched to the good battery and got about 13.5 or so at idle, switched to the old one and got about 11.5 or so at idle. Figured it was just down, but it never got better the whole time (I was only out about 20 minutes prop testing some loaners). Shame on me for leaving it on BOTH I guess.

I run with my batteries on both also.

I blew up a die hard in my face when I was jumping a car when I was about 17 years old. It certainly was a die hard, it started the car for about a month after that, and it was an old one out of my mom's car when I got it.

Here is what happens with a dead short. China Syndrome.:(

Joe,

I've seen posts melt off of healthy batteries, if the cable connection was bad. Happened to a new set of 32 volt Rolls batteries on a friend's boat. One cable was left loose. Several days of starting those big detroits and then no juice. Went down expecting a breaker reset and found a puddle of lead and a bunch of smoke. Could have been scary.

I've got pix of the royal McGyver fix I out on it to get it from Marathon to Lauderdale where they had a rpelacement waiting for us. I'll dig it up for you guys...

The battery on the right was exactly one week old. I'm still not sure what caused it, but I think it was a bad rebuilt starter I bought. I saw the battery post glowing red like a burner on an electric stove. It was damn tough to reach down and take that cable off.:eek:

Foul,
Getting back to your original post , since you didn't try it first , the "new" alternator could have been bad. That's the reason the somewhat low volt reading on the dash. As you ran the boat that day , you slowly discharged the batteries till it quit and of course at that point wouldn't restart.
Also since the alternator was so hot , it too , could have had a short.
Best bet??? Change the batteries and the alternator. By now the batteries probably aren't much good and you likely fried the alternator. Any decent auto store should be able to test the alternator if you want to try to save the price of a new one.

OK cuda , just what does cardisoma guanhumi mean???
NO biminis:D :D

In a later post you said that the optima showed 13+ volts. The old batt showed 11.5, and both together showed 12.5

This indicates a lame cell on the old batt. Did you check the cells with a floaty thing (a battery tester that checks specific gravity of the electrolyte)? That will tell you a lot.

I know the new battery is good.... I loaned it for a few days to the neighbor to get her truck to the auto repair shop. It worked fine for her. As for the old one, on the garage floor later that same day, it showed 9 volts on my tester. It's toast.

As for the alternator, saying it was "new" is kind of a misleading statement. I put it the last week of April or so, the motor quit running on the 22nd of June. Between those two days, nothing out of the ordinary happened.

Do any of you guys install a "fusible link" between the battery and the alternator? Cars come with them standard... just in case the alternator shorts , the wiring won't melt down. I installed them on my boat... One suggestion.... if you have two batteries and one engine and charging system... run the boat with the switch on "both"... then when anchored switch to "one". Save battery "two" for starting the motor. On twin engine boats.. run the battery switches with one switch on "one" and the other switch on "two". Then switch one to "off" when anchored.

As far as rpm for the alternator is concerned... automotive alternators are meant to turn lots faster than most boat motors run. Think of the abuse they get in a car... constantly getting cycled up and down through the rpm range.. much more so than on a boat application. The only side effect of too much rpm's is the brush to the rotating field will wear a little quicker and the wear on the bearings...