High Amp Alternator Problems!!

I thought I'd drop a post here to see if anyone has come across this problem so that I may diagnose what's going on with mine. A few weeks ago we were forced to cut our boarding short due to the boat was losing power. The alternator aparently was not putting out voltage. I thought I popped an alternator. The alternator I have is the 150amp from the BatteryShack in Florida. Anyway, I pulled the alternator and replaced it with my stock alternator. I tested it at the ramp and it was putting out the proper voltage. Then it stopped. I had my 150amp alternator tested and it's putting out 14.4 volts and 115 amps. (The guy couldn't spin it any faster on his bench or it would have put out 150) The alternator is good. So, tonight I put it back in and tested it. Just an FYI, I do have a large system in the boat. I'm running three amps, one being a 1000W sub amp and the other two being Alpine V12's at 700W max each.

Now during all my testing I have taken the system offline. Tonight I had it offline, I started the engine and it instantly went up to 14.5 volts. Then after a few minutes it stopped generating. Then it would generate voltage and then stop again. Then it would, I'd kill the engine, start it and it wouldn't generate any voltage.

Why would an alternator turn on and off like that? It is self exciting and the batteries are fully charged. Could I have caused a problem in the voltage regulator on the alternator with my system during this past summer of bumping my system and subs pretty hard? I run two Optima batteries with a third battery on an isolator. I have alternator guys stumped on this one. I was wondering if any of you have had this issue. My engine is the Indmar 5.7 fuel injected.

I need help from the electrical guru's!!!! Sorry for the long post but it was needed to explain what is happening.

Im sure Rod will have a answer for you. But to me it sounds like the internal voltage regulator. I had a Bat Shack 150 Amp Alternator. They use a internal self exciting regulator. When my bat shack alternator blew up I had a local company re-build my Battery Shack alternator. They said the internal self exciting regulator was the cheepest reguator you can get. As soon as they replaced it with a heavy duty regulator all was good.

P.S make sure your alternator has the spark arrestor mess gaurd's on your alternator Bat Shack has had a bad rep for not putting them in

Where does the charge wire go from the alt? Mine runs from the alt to the starter then to the battery's. Had an issue at the starter and ended up having similar issues as you. Bypassed the starter and all is well again.

Grant- I was wondering if it was the internal voltage regulator. From my experiences with the Bat Shack I was assuming it was the cheapest. The way it's acting sounds like it's the regulator. However, my stock alternator was doing the same thing last week when I put it in. It was charging then it all of a sudden shut down. I haven't done anything else with it because I put in the 150amp back in. I think I'll have it opened up by the local shop I use to have them take a look at it.

Phaeton- Yes, the wire goes from the alternator to the starter solenoid then to the batteries. You had this same problem? I was wondering if the starter solenoid is causing a problem. How and why would it be doing it now and not all this or last year? Hmmmm.......

Thanks guys for some real world experience with this problem and what you guys did to remedy the problem. Anyone else have this problem as well?

My Charge wire goes from the back of the Alternator directley to the Battery solonoid

Run your charge wire direct to your battery switch/solonoid. This takes the starter out of the loop which it does not need to be there. Mine had a week connection at the starter but was hard to detect until it completly failed.

Travis

Kraig,
Be sure to check the voltage level from the Alt AT the Alt....not the battery. Reason here is that some connections may be between the Alt and the battery, i.e. a terminal on the starter is common.
Although the output should reach the battery, if you have a high resistance connection somewhere between the alt and the battery, checking at the battery may not be telling you if the alt is good or not.
I wish I'd have taken a pic but I recently melted an insullator surrounding the terminal lug on the starter where the 4 ga. alt line then connects to the 2/0 bat cable. This eventually ended up causing a complete open circuit.
good luck

Thanks guys for all your input. I just went and picked up a wire to run from my alternator directly to my batteries. I did check the voltage at the alternator and the batteries. The difference was about .10 of a volt. My thoughts are to disconnect my two Optima batteries from each other. Disconnect the charge wire from the alt. to the starter solenoid. Run a wire directly from the alt. to one battery. And keep the other battery hooked up to the starter solenoid to run the engine. Then see what the alt. does. This takes the starter solenoid out of the loop temporarily to see if it's the problem. I'll be doing this tomorrow after I go ride with some frinds on their boat.

Any more suggestions? I'll tell ya the results tomorrow. Again, thanks for all your help guys!!

Ok, here are the results.... I used two batteries to test the alternator and starter solenoid. I ran the battery cables from the engine and starter solenoid. I disconnected the alternator from the starter solenoid and ran a positive cable from the alt. to a separate battery. Of course these two batteries were linked with a negative cable to complete the circuit for the alt. The alternator never put out a charge!

I isolated the alt. and it still didn't put out a charge. Last time I tested it, like I said above, it would put out a charge and then it would shut down. It would turn on and off. Would this be an indicator of a bad voltage regulator? When I had it tested at a shop it was putting out 14.4 and plenty of amps. Can a bad voltage regulator have these symptoms?

Grant- Did your voltage regulator have these symptoms in your alt. from the Batt. Shack?

IMO: bad voltage regulator.

Another thing to remember is your HO alternator will only do 1 or the other, It will give you 14.4 volts and no be throwing no amp's Or it can be pushing 150 amp's and showing 12. volts,

I second grant's conclusion...cheap parts can be intermittent....I ran into a similar issue on a 135 amp alt. from ebay. Had an alt repair shop open it up....said they were very cheap parts.

You said you never had that alt fully tested (the guys machine woudln't turn fast enough)Most (not all) high end alt don't produce high amp at low RPM, you will rarely see more than 3000-3500 RPM's on your boat....why have such a beefy alt that you'll never get the full juice out of. A good alt shop can build you a solid 115-120 amp alt that will hang (lower, but close) w/ bigger 140+amp alt in the 3k range, w/o putting a 150amp strain on your motor. IMO big alt (150 amp) are not a good idea, if you run your batteries low ( i know I do) , and try and take them to a full charge on such a large alt...your asking for trouble (can easily cook your batteries) Alt are not battery chargers. Just some FYI.

(Message edited by acurtis_ttu on October 03, 2005)

Kraig:

What confuses me the most is that you said the old, stock alternator does essentially the same thing. I can imagin a number of different things that could cause the symptoms but I would think it very unlikely that it would effect two different alternators the same way!

Ignoring the stock alternator for a moment:

A concern with a high output alternator is it overheating. It can get pretty hot in the engine compartment and if the alternator is really cranking out the amps it is going to heat up a lot and need all the cooling it can get. It is possible that it has protection from overheating and shuts down, which would allow it to work again. It is also possible that it was damaged from overheating.

If you feel comfortable taking the alternator apart then I would suggest inspecting the brushes. Normally, alternator brushes last a LONG time, but it is possible that overheating has caused the brushes to fail early. Sometimes working, sometimes not is a common characteristic of bad brushes.

Another possibility, that could even explain similar problems when reverting to the stock alternator, is that for some reason the alternator is not making a good ground connection. This seems so unlikely, though, as it should get a reasonable ground through either the pivot point bolt or the adjustment bolt. You might want to check to see if there is a ground difference between the battery and the alternator case when it is actually working.

The only other thing that I can think of is some sort of a bad connection around the internal voltage regulator. Again, if the alternator got hot enough to melt solder then internal connections could go bad: sometimes they make contact and work, other times they lose contact and it stops working. Temperature and vibration will often make it go from one mode to the other.

Adam , the thing with big amp alternators (i think) is that no one is running them on boats with a stock deck/no amps and only one battery. If a stock alt puts out 65 amps like mine DID and it is charging 1 battery then a 150 spread across 3-4 or even more batteries AND running three amps isnt putting anywhere near 100 amps into one battery unless you have a major problem in the boat. This is my delema right now as sat evening as we were about to take a 40+ mile ride to get dinner and smashed the alternator died at the right time, while we were putting the boat in. It did not die at the destination point or 15 miles after we left the dock where i would have had to make an important decision sober
Do i spend the dough to get the bigger alternator or just get mine rebuilt to a 95 amp when i know good and well my one amp alone can draw over 100 amps with the tower turned up??

Bob, I see your point. I had issues running a 140 amp alt.....never had a problem with stock. went to a HD 95 amp alt (I think) tweaked to about 110 amp. That put out decent amps at low RPM and never had an issue. What amp are you running that will pull 100 amps? I have 4 amps in my boat running only two batteries, stock alt 65/70amp. while I don't see 14.2-14.4 volts I still get in the high 13.8-13.9. Are you using all class a/b or do you have D? 1 jl 10 w-6, NVS 1010's, 4 polk interior.

Ok, here's what I found out about my HO alt. I had it retested at a local shop after it wouldn't put out a charge. It didn't work for them this time. They opened it up and saw evidence of it getting pretty hot. Their first thoughts was that it was built pretty cheap. So, now they're going to build me one that is alot stronger. The good news is that they are local and if I have any problems I just take it over to them.

They said the ones they build are around 180 amps. Adam- Why is a HO alt. not a good idea? How does it put a strain on the engine? I'm not doubting it, just wondering how.

My system consists of two 700w Alpine V12's and one class D Xtant 1000w sub amp. Given what I have, do I need an alternator that large? Like I said, this last one does have evidence of getting hot. I also run two deep cycle batteries as my mains and one more on an isolator. I am planning on adding a capacitor or two to my system. Any suggestions on which ones, sizes and how to wire them up? I know how much cap. storage I need, but is it better to get it all in one cap. with all three amps wired to it or is it better to break them up and put a cap. in-line to each amp? Some larger caps. come with a distribution block built in and makes it very easy and neat to wire.

(Message edited by kraig on October 04, 2005)

You have three amps, and they run at 100 amps?!?!?! I run three Orion HCCA's - two 225 and a 250, and pull about 150 for all three, TOTAL. All three are running at 1 ohm or under, so I know they draw the juice. And HCCAs are notorious class a/b current hogs.

Kraig, seems like that alternator and two deep cells are OK for your system. My alt was rebuilt for 125 and I have two blue tops for the system, another for the main, everything works good. My last boat had similar set up for almost seven years and no problems.

(Message edited by jeff359 on October 04, 2005)

I don't understand your question Jeff? Where did I say they run at 100 amps? Maybe I'm missing something in your question...

Sorry for mixing two responses. That was in response to someone a few posts ahead of you.

I was told a good guide for alternator is add up your draw and split it in half. So if you add 150 amp draw, you should add 75 to the amp output. Also on the capacitor, wait to get some advise from some of the stereo gurus around here. I've been told it isn't worth it if your wiring and charging is up to snuff (which your's appears to be.)

713-692-0507 ask for finch. (kinda redneck, but knows his s_it) he'll answer any questions you have regarding alt. He's been building alt for 30+ years.

My 800 watt soundstream has a max recommended fuse/circuit breaker or 140 amps. I put a 100 amp breaker in to try to protect my tower speakers as i didnt want the full power going there but the breaker pops just as it really starts sounding good. I also have a 600 watt RF and a 400 watt RF but that one is only doing half duty so im looking at 1600 watts rms. Now we know these amps arent even efficient especially the A/B ones so in order to get that kind of power tack on another 1000 watts of heat and i could be using 2600 watts of power? Even at the most efficient 13.8 volts im still drawing 188 amps. We know i dont run at the top all the time but im still drawing 70-90 amps constantly and the batteries need a boost after sitting idle and crancking the tunes. On top of all this the alt shop didnt even recognize my mounting as standard for a boat (2001 merc with 5.0) He can rebuild it but it will be stock once again?????? 65 amps just dont cut it.

Craig: Where are you getting this 180 amp alternator from? and whats it costing? Autoletrics in Camble Ca said that the higher you go with Amp output the harder time it has throwing out voltage below 1000 rpm's. They said 130 amps is what they have found to be a good balance between high output and not haveing to have high rpm's to get 13.4 volts. And if you can watch them when they test the alternator to see what kind of voltage you are pushing at 180 amp's that would be great.
FYI: most HO alternators will not push max amps for very long. When a alternator is pushing more than 100 amp's its getting Hot. Real hot. Feel the alternator after they test it and you will see how much heat is generated. Heat is what kills most alternators. Some alternators have a thermostat the regulates the Voltage depenging on heat. More amps= more heat. And when you push your system and run your batterys real low your alternator is gonna have to work real hard to charge back up. Thats where lots of people blow up the alternator. (I have done it) So IMO the solution is battery's run as many as you can run. And a HO alternator to manitaine them, and not running your system super low. Im guilty of this. 10.5 volts and my W-7's start shutting off. And yes I have payed the price. Blowen alternators ect. And for the people that say they are pushing or pulling 100- amp's how are you testing this. I test with a amp clamp. This is the best way to see what you are pulling. I have tested boats that are pulling 300 amp's on a heavy bass notes.

I thought it was explained but i guess i neglected to mention it in my last post where i said i was using a 100 amp breaker for my tower amp and it pops frequently if i turn the tower just a bit too high and the gain is set around 6/10ths of the way up as i didnt want to get too crazy and blow the tower speakers.
Now here is the real problem: I went by the alternator shop yesterday and the owner told my my body/frame is smaller then all the standard alternators out there. It is 6" from top hole to bottom hole. It is on a 2001 merc 5.0 and he seems to think there isnt a hi amp kit for it. So now im left with either adapting the slightly taller standard delco 6.7" or going back to a stock 65 amp which would be stupid as it will cook itself in no time and it cost more for him to repair then build a 95 amp version and just make an adapter bracket???

Bob, what do you have on your tower? What model# are the RF's? Soudnstream?
Have you ever tested how many amps your system is pulling? Just a thought, but fuses can/will blow from other reasons than your amplifiers pulling to many amps.
Reason I say is that I'm pushing close to that amount of RMS wattage (1500) jl 500/1, (2) audobahn 8000t, stock Kenwood 4ch -240 RMS. I've never had issues with popping fuses ( I use breakers instead of fuses)

Well the soundstream is a VGA 800.2 with a max RECOMMENDED fuse/breaker of 140 amps which doesnt mean i need a 140 just that is the top limit so i figured with a 100 amp breaker id be protecting the speakers from the full kick or the 800. The other amps are on seperate appropriate fuses and havent had any problems. I do have a clamp on amp meter i borrowed from work and will be testing the system shortly, just havent had time since im working the alternator issue. I think that thing is rated to 200 amps ac or dc, crazy current.

http://www.arcomarine.com/catalog.htm

Heres a good site on batts, alternators, starters, and wiring

Grant are you running a large body alternator and what style/model clamp on amp meter are you using? Ive got a fluke thing (dont have the model number right here) and im very suspicious of my readings even though its a work meter and is cal'd yearly.