Alternator update

[Ryan Turner]

To those of you who responded to my earlier post regarding a failed alternator (or anyone else who's interested), here's an update.

Recall that I thought my alternator had always acted finicky (sp?) because it wouldn't kick into gear until the engine reached about 1,500 rpm. From that point it would always work great at any engine speed. Then it quit altogether one day. Everyone suggested that I check all the electrical connections in the alternator circuit. I did that and found them to all be good. I then shopped around for a marine alternator and three-step regulator. The WM price -- $600 to $700 for the pair! Yikes, I thought, perhaps I don't really need the fancy package. So I decided to remove the old alternator and bring it to a shop for testing. They tested it and found that it wasn't putting out any power. So they rebuilt it at a cost of $107.95. It works great now. And it still won't kick into gear until I get the engine up to about 1,500 rpm. It must just be something about the alternator. There's nothing special about it. It's a Delco-Remy unit built for a car of some sort. But it charges my batteries just fine and it didn't cost an arm and a leg. Suites me fine.

Ryan Turner
s/v Zenobia
CD33 hull no. 100
Oriental, NC



rdtec@aol.com

[Tom]

To those of you who responded to my earlier post regarding a failed alternator (or anyone else who's interested), here's an update.

Recall that I thought my alternator had always acted finicky (sp?) because it wouldn't kick into gear until the engine reached about 1,500 rpm. From that point it would always work great at any engine speed. Then it quit altogether one day. Everyone suggested that I check all the electrical connections in the alternator circuit. I did that and found them to all be good. I then shopped around for a marine alternator and three-step regulator. The WM price -- $600 to $700 for the pair! Yikes, I thought, perhaps I don't really need the fancy package. So I decided to remove the old alternator and bring it to a shop for testing. They tested it and found that it wasn't putting out any power. So they rebuilt it at a cost of $107.95. It works great now. And it still won't kick into gear until I get the engine up to about 1,500 rpm. It must just be something about the alternator. There's nothing special about it. It's a Delco-Remy unit built for a car of some sort. But it charges my batteries just fine and it didn't cost an arm and a leg. Suites me fine.

Ryan Turner
s/v Zenobia
CD33 hull no. 100
Oriental, NC

It helps us all to learn of the final outcome of problems that we all may face one day. So thaks for t aking the time to post.



TomCambria@mindspring.com

[D. Stump, Hanalei]

Ryan,
A quick way to tell if the alternator is working, is to first check the state of charge meter for each battery. Then start the engine, and with it at idle rpm (tach may not be indicating)look at the state of charge meter again. It should, in a few seconds, start to show a higher state of charge, because the alternator is charging the batteries. On Hanaleis' meter, it will start with a yellow indication, and go to green very shortly. Anyway, glad you didn't have to spend the outrageous bucks for a "Marine" alternator.

Dave Stump
Captain Commanding
s/v Hanalei CD-30

[Larry DeMers]

Ryan,

I am still concernedabout your alternator not putting out current when the engine is first started. My CD30 puts out current immediately..in fact, I was hearing a longish"chirrrp" as the alternator came up to speed upon engine starting. Turned out to be an alternator bolt ready to fall out, loosening the belt, and allowing the fully loaded alternator to lock, making the slipping belt chirrrp.

SO your system is meant to output current soon as it produces enough voltage to energize the field windings. THe fact that it has to go up to 1500 rpm before this happens says something else is wrong, and that the fialure of your alternator was probably associated with whatever IS wrong.
Don't give up looking for the problem..it's still there.

sorry.

Larry DeMers
s/v DeLaMer
Cape Dory 30

To those of you who responded to my earlier post regarding a failed alternator (or anyone else who's interested), here's an update.

Recall that I thought my alternator had always acted finicky (sp?) because it wouldn't kick into gear until the engine reached about 1,500 rpm. From that point it would always work great at any engine speed. Then it quit altogether one day. Everyone suggested that I check all the electrical connections in the alternator circuit. I did that and found them to all be good. I then shopped around for a marine alternator and three-step regulator. The WM price -- $600 to $700 for the pair! Yikes, I thought, perhaps I don't really need the fancy package. So I decided to remove the old alternator and bring it to a shop for testing. They tested it and found that it wasn't putting out any power. So they rebuilt it at a cost of $107.95. It works great now. And it still won't kick into gear until I get the engine up to about 1,500 rpm. It must just be something about the alternator. There's nothing special about it. It's a Delco-Remy unit built for a car of some sort. But it charges my batteries just fine and it didn't cost an arm and a leg. Suites me fine.

Ryan Turner
s/v Zenobia
CD33 hull no. 100
Oriental, NC

demers@sgi.com

[D. Stump, Hanalei]

Larry,
Do ya think it could be the oil pressure sender sensor? I read on another site that sometimes the instrument panel will not respond until oil pressure is sensed. That person thought it would be a good idea to change the sensor. Hanalei responds the same as Ryans' CD, but it never bothered me. And, I know my alternator is okay, as I just had it rebuilt too!

Dave Stump
Captain Commanding
s/v Hanalei CD-30

P.S. Hanalei is minus stays'l and main boom, fresh water is winterized, she goesw on the hard next week, and the Captain will be on half pay for the winter....Boo Hoo!!!

[Chris Reinke (CD330 Innis]

Larry / Ryan - I can offer the following as an FYI - My CD330 has the same characteristics and the alternator shop said it was in the voltage regulator and not in the alternator. The tachometer and amp meter are both supplied by the alternator and neither one indicates anything until the RPM's are brought up. Once the regulator kicks in and the field is energized then everything works as the RPM's are reduced. The alternator shop said it had something to do with starting at low RPM's and that the regulator takes a moment to identify the charging needs. I do not know for a fact but I believe my alternator output is minimal until the guages kick on, and then everything works just fine. Perhaps this is the difference between a "marine" and a "car type" alternator voltage regulator.

Good Luck,
Chris

Ryan,

I am still concernedabout your alternator not putting out current when the engine is first started. My CD30 puts out current immediately..in fact, I was hearing a longish"chirrrp" as the alternator came up to speed upon engine starting. Turned out to be an alternator bolt ready to fall out, loosening the belt, and allowing the fully loaded alternator to lock, making the slipping belt chirrrp.

SO your system is meant to output current soon as it produces enough voltage to energize the field windings. THe fact that it has to go up to 1500 rpm before this happens says something else is wrong, and that the fialure of your alternator was probably associated with whatever IS wrong.
Don't give up looking for the problem..it's still there.

sorry.

Larry DeMers
s/v DeLaMer
Cape Dory 30

To those of you who responded to my earlier post regarding a failed alternator (or anyone else who's interested), here's an update.

Recall that I thought my alternator had always acted finicky (sp?) because it wouldn't kick into gear until the engine reached about 1,500 rpm. From that point it would always work great at any engine speed. Then it quit altogether one day. Everyone suggested that I check all the electrical connections in the alternator circuit. I did that and found them to all be good. I then shopped around for a marine alternator and three-step regulator. The WM price -- $600 to $700 for the pair! Yikes, I thought, perhaps I don't really need the fancy package. So I decided to remove the old alternator and bring it to a shop for testing. They tested it and found that it wasn't putting out any power. So they rebuilt it at a cost of $107.95. It works great now. And it still won't kick into gear until I get the engine up to about 1,500 rpm. It must just be something about the alternator. There's nothing special about it. It's a Delco-Remy unit built for a car of some sort. But it charges my batteries just fine and it didn't cost an arm and a leg. Suites me fine.

Ryan Turner
s/v Zenobia
CD33 hull no. 100
Oriental, NC

[Dennis Ward]

To those of you who responded to my earlier post regarding a failed alternator (or anyone else who's interested), here's an update.

Recall that I thought my alternator had always acted finicky (sp?) because it wouldn't kick into gear until the engine reached about 1,500 rpm. From that point it would always work great at any engine speed. Then it quit altogether one day. Everyone suggested that I check all the electrical connections in the alternator circuit. I did that and found them to all be good. I then shopped around for a marine alternator and three-step regulator. The WM price -- $600 to $700 for the pair! Yikes, I thought, perhaps I don't really need the fancy package. So I decided to remove the old alternator and bring it to a shop for testing. They tested it and found that it wasn't putting out any power. So they rebuilt it at a cost of $107.95. It works great now. And it still won't kick into gear until I get the engine up to about 1,500 rpm. It must just be something about the alternator. There's nothing special about it. It's a Delco-Remy unit built for a car of some sort. But it charges my batteries just fine and it didn't cost an arm and a leg. Suites me fine.

Ryan Turner
s/v Zenobia
CD33 hull no. 100
Oriental, NC

Ryan, My CD33 with a Volvo MD11C, starts charging at 600 to 800 rpm. One thing you might think about is the relative sizes of the pulleys. My altenator belt runs from the outside of the flywheel (large diameter pulley to the small diamerer altenator pulley ). This must give me the required RPM early in the game,



DWard34@aol.com

[Tom]

Ryan,
A quick way to tell if the alternator is working, is to first check the state of charge meter for each battery. Then start the engine, and with it at idle rpm (tach may not be indicating)look at the state of charge meter again. It should, in a few seconds, start to show a higher state of charge, because the alternator is charging the batteries. On Hanaleis' meter, it will start with a yellow indication, and go to green very shortly. Anyway, glad you didn't have to spend the outrageous bucks for a "Marine" alternator.

Dave Stump
Captain Commanding
s/v Hanalei CD-30

Dave, the problem with that is that if you have a broken wire or bad connection the alternator may be OK but you still wouldn't get a charge. What we were trying to do for Ryan from his original post was to make sure it was the alternator that was bad and not the wiring.



TomCambria@mindspring.com

[John]

To those of you who responded to my earlier post regarding a failed alternator (or anyone else who's interested), here's an update.

Recall that I thought my alternator had always acted finicky (sp?) because it wouldn't kick into gear until the engine reached about 1,500 rpm. From that point it would always work great at any engine speed. Then it quit altogether one day. Everyone suggested that I check all the electrical connections in the alternator circuit. I did that and found them to all be good. I then shopped around for a marine alternator and three-step regulator. The WM price -- $600 to $700 for the pair! Yikes, I thought, perhaps I don't really need the fancy package. So I decided to remove the old alternator and bring it to a shop for testing. They tested it and found that it wasn't putting out any power. So they rebuilt it at a cost of $107.95. It works great now. And it still won't kick into gear until I get the engine up to about 1,500 rpm. It must just be something about the alternator. There's nothing special about it. It's a Delco-Remy unit built for a car of some sort. But it charges my batteries just fine and it didn't cost an arm and a leg. Suites me fine.

Ryan Turner
s/v Zenobia
CD33 hull no. 100
Oriental, NC

From my experiences the alternator should be charging immediately upon engine starting. You should have a charging system condition indicator light at the engine panel. Is it on or off when the engine is started? It should be off. Obviously it goes without saying, if it stays on you've got a problem. With the engine at idle check alternator output with an ammeter. It should be charging something because your starter has just drawn down a lot of current from the battery. My Balmar charges immediately at about 500 rpm idle, the ammeter usually shows about 40 amps and then immediately starts tapering down until it barely reads on the meter scale around 1 amp or so after about ten - fifteen minutes of running time, just as it should. It is running through a single stage regulator at the present time.

Right after an engine starts voltage in the battery will be relatively low and so the regulator will supply more "field" current to the alternator which will then put out more charge current as a direct result. That current will continue until battery voltage nears output voltage and the regulator tapers off the charge from the alternator.

Alternator pulley size is critical for the alternator to turn the proper rpm to produce output current with the engine at idle. I have seen tachometers that won't read properly until rpm's are run up and then reduced and then they read properly. I've never experienced that problem with alternators.

I agree with Larry, you still have a significant problem. I would guess a regulator problem, but it could be an incorrect pulley on the alternator. Have the alternator shop test it for output at a given rpm, say 500, and see if it is outputing if you don't have your own ammeter. Make sure your grounds are good and clean without any corossion and are very tight.

I have the formula somewhere for calculating the proper alternator pulley size and I'll post it in another message if I can find it.

By the way, what parts did the shop replace? What exactly did they say they did to get it to output? Brushes, commutator cleaning, regulator repairs?

[MARK GUINAN]

To those of you who responded to my earlier post regarding a failed alternator (or anyone else who's interested), here's an update.

Recall that I thought my alternator had always acted finicky (sp?) because it wouldn't kick into gear until the engine reached about 1,500 rpm. From that point it would always work great at any engine speed. Then it quit altogether one day. Everyone suggested that I check all the electrical connections in the alternator circuit. I did that and found them to all be good. I then shopped around for a marine alternator and three-step regulator. The WM price -- $600 to $700 for the pair! Yikes, I thought, perhaps I don't really need the fancy package. So I decided to remove the old alternator and bring it to a shop for testing. They tested it and found that it wasn't putting out any power. So they rebuilt it at a cost of $107.95. It works great now. And it still won't kick into gear until I get the engine up to about 1,500 rpm. It must just be something about the alternator. There's nothing special about it. It's a Delco-Remy unit built for a car of some sort. But it charges my batteries just fine and it didn't cost an arm and a leg. Suites me fine.

Ryan Turner
s/v Zenobia
CD33 hull no. 100
Oriental, NC

Ryan, My CD33 with a Volvo MD11C, starts charging at 600 to 800 rpm. One thing you might think about is the relative sizes of the pulleys. My altenator belt runs from the outside of the flywheel (large diameter pulley to the small diamerer altenator pulley ). This must give me the required RPM early in the game,

You are right... the rotor shaft in an alternator must be turning a certain rpm in order to build the magnetic field strong enough for the stator to send juice to the rectifier and hence to the battery. A change in pully diameter would transfer more rpm to the shaft with fewer rpm's from the motor or vice versa. As for the Delco Remy alternator being for "some car" I doubt it...it sounds like a Heavy Duty unit made for a diesel truck engine.



MGUINAN702@AOL.COM

[Larry DeMers]

Hi Guys,

Dave, you might have something there..that certainly would explain the situation, and could be easily tested (fake the "oil Pressure" being up by grounding the wire to the sensor?? Then start the engine and see. Does this effect take place even when the engine has been run for awhile? (Would expect it to go away as the engine is warmer, oil pressure comes up faster etc.).

The other thought I had was pulley ratios. Auto type alternators have a different charge curve than do boat type alternators. They are meant to operate in the 2500-3000 rpm range, rather than the lower 1000-2000 rpm of marine alternators. Some of this can be compensated for with pulley ratios..to a point. Hmmm..since all of your alt's do this, then there is probably nothing wrong with it..just a characteristic of the time needed to read the charge necessary I guess, although I have never experienced it in any vehicle or vessel I have worked on.
Interesting problem!

Cheers All,

Larry DeMers
s/v DeLaMer ..also up on the hard for the winter..booo! Already miss
her...

Larry,
Do ya think it could be the oil pressure sender sensor? I read on another site that sometimes the instrument panel will not respond until oil pressure is sensed. That person thought it would be a good idea to change the sensor. Hanalei responds the same as Ryans' CD, but it never bothered me. And, I know my alternator is okay, as I just had it rebuilt too!

Dave Stump
Captain Commanding
s/v Hanalei CD-30

P.S. Hanalei is minus stays'l and main boom, fresh water is winterized, she goesw on the hard next week, and the Captain will be on half pay for the winter....Boo Hoo!!!

demers@sgi.com

[Ryan Turner]

By the way, what parts did the shop replace? What exactly did they say they did to get it to output? Brushes, commutator cleaning, regulator repairs?

The shop replaced the regulator, the rectifier, and a set of diodes. All these items were brand new. An interesting note: they said the alternator was originally rebuilt using used parts that had been sand blasted clean to look new. Apparently all alternator rebuilds are not created equal.

[Joe Wysong]

To those of you who responded to my earlier post regarding a failed alternator (or anyone else who's interested), here's an update.

Recall that I thought my alternator had always acted finicky (sp?) because it wouldn't kick into gear until the engine reached about 1,500 rpm. From that point it would always work great at any engine speed. Then it quit altogether one day. Everyone suggested that I check all the electrical connections in the alternator circuit. I did that and found them to all be good. I then shopped around for a marine alternator and three-step regulator. The WM price -- $600 to $700 for the pair! Yikes, I thought, perhaps I don't really need the fancy package. So I decided to remove the old alternator and bring it to a shop for testing. They tested it and found that it wasn't putting out any power. So they rebuilt it at a cost of $107.95. It works great now. And it still won't kick into gear until I get the engine up to about 1,500 rpm. It must just be something about the alternator. There's nothing special about it. It's a Delco-Remy unit built for a car of some sort. But it charges my batteries just fine and it didn't cost an arm and a leg. Suites me fine.

Ryan Turner
s/v Zenobia
CD33 hull no. 100
Oriental, NC

Let me add another voice to the Greek chorus. On our Cape Dory 330 with a high-output Balmar alternator, the rpm meter didn't/doesn't kick in until about 1200 rpms both before and after the rebuild mentioned before. Once it does kick in, the meter continues to work at lower/higher rpms until the engine is shut down. It then needs to reach about 1200 the next time it is started before kicking in.

I don't know why, but as the rebuild is charging just fine, I am holding with the old adage "If it ain't broke, don't fix it."

Which reminds me of a sign on the wall of a Volkswagon repair shop in Tremont, Maine (circa 1975)-- "If we can't fix it, it ain't broke."

Joe




tgjournal@gestalt.org

[John]

By the way, what parts did the shop replace? What exactly did they say they did to get it to output? Brushes, commutator cleaning, regulator repairs?

The shop replaced the regulator, the rectifier, and a set of diodes. All these items were brand new. An interesting note: they said the alternator was originally rebuilt using used parts that had been sand blasted clean to look new. Apparently all alternator rebuilds are not created equal.

Ryan,

I haven't been able to find that pulley ratio formula as yet, but I'll keep digging. Even though they said they replaced the regulator I still have a suspicion that's where the problem lies. It wouldn't be the first time a bad apple was taken right off the shelf.
Good luck to you, let us know if you ever resolve the mystery.