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xbrdr1
04-17-2012, 10:23 AM
I have a new 55a alternator and battery for my 2001 205V. I realized an issue when voltage would slowly drop. A voltmeter test at the alternator at 2000RPM showed 11.65 volts.

I am really at a loss of what this could be? Regulator possibly? :confused:

CantRepeat
04-17-2012, 10:28 AM
I have a new 55a alternator and battery for my 2001 205V. I realized an issue when voltage would slowly drop. A voltmeter test at the alternator at 2000RPM showed 11.65 volts.

I am really at a loss of what this could be? Regulator possibly? :confused:

Probably the alternator it self is going bad or the regulator inside it.

xbrdr1
04-17-2012, 10:41 AM
Sorry Jim I forgot to mention...rebuild shop said the alternator is great

thatsmrmastercraft
04-17-2012, 11:14 AM
Bad connection somewhere. Battery terminals, ground on block or wire from alternator to battery. Loose belt could do it, but it would have to be really loose.

What voltage did the shop see when they tested the alt? If tested good, that would preclude the regulator as it is within the alt.

xbrdr1
04-17-2012, 11:54 AM
Thanks. They saw 14.5. So, something was causing the alternator to put out low current but, probably, high amp. How about the heavy gauge wire from Batt to Starter?

thatsmrmastercraft
04-17-2012, 11:57 AM
Thanks. They saw 14.5. So, something was causing the alternator to put out low current but, probably, high amp. How about the heavy gauge wire from Batt to Starter?

That would only cause a starting problem. Once the key is released from the start position, that circuit is disconnected.

Battery terminals, ground on block or wire from alternator to battery are you odds on favorites. Or bad battery.

rd1900
04-17-2012, 12:00 PM
You can check the alternator directly, from the big stud on the back to the alternator body (with a volt meter of course). If it isn't 14.5 volts, the alternator has a problem (assuming there is not some obvious belt problem.) If you do get 14.5 volts, then the problem is with with wiring somewhere, perhaps at the starter solenoid.

thatsmrmastercraft
04-17-2012, 12:04 PM
You can check the alternator directly, from the big stud on the back to the alternator body (with a volt meter of course). If it isn't 14.5 volts, the alternator has a problem (assuming there is not some obvious belt problem.) If you do get 14.5 volts, then the problem is with with wiring somewhere, perhaps at the starter solenoid.

The wiring at the starter solenoid would not affect the charging circuit(unless an actual short to ground). Separate circuits.

EricB
04-17-2012, 12:08 PM
You can easily test the positive and negative wiring for the alternator by performing volyage drop tests. The Voltage drop test checks the integity of the feed and ground (+ & -) circuits under dynamic conditions (operating and performing).
Using a DVOM set on the volt scale(DC), clip one lead to the output post of the alternator and the other lead to the positive terminal of the battery. Start and run engine. The Voltmeter should read less than 0.5 volts.
To test the ground side, clip one lead to the alternator case and the other to the battery negative terminal. Start and run and voltmeter should read less than 0.5 volts.

xbrdr1
04-17-2012, 06:31 PM
Thanks guys. Can you tell me where the orange, purple and black wire should run to from the alternator?

Jeff d
04-17-2012, 06:38 PM
I can't remember which colors are which. One is a ground for the regulator (black?), one is key on power (purple?), and the other is the charging lead which goes to the battery side of the main breaker (pretty sure this is the orange). It's important to note that the charging wire goes to the battery side of the breaker and not through it. So, it was just a convenient place for them to give it a path back to the battery and the state of the breaker doesn't have an effect on the alternator's ability to charge.

xbrdr1
04-17-2012, 08:18 PM
Traced the orange back... Not too bad. The black wire traced all through the harnesses.. Never did fine where that went... I believe that is the culprit, since the connector at the alternator is rough. I suppose I could splice... But I was hoping to replace with thicker gauge

xbrdr1
04-18-2012, 09:18 AM
Should that black/ground wire from the alternator connect to the engine block somewhere? or to a connector? I'm surprised it's this 'tucked' away and runs like it does through the harnesses.

thatsmrmastercraft
04-18-2012, 10:13 AM
If you suspect the problem to be a bad alternator ground, clip a jumper wire from the Alternator case/bolt to the engine block and see if your voltage changes.

After reading the thread again, when did this problem start? Did you replace the alt and battery to fix this, or did this come about after replacing the alt and battery?

xbrdr1
04-18-2012, 10:44 AM
Thanks Peter... How I first noticed was perfect pass rebooting! I discovered that was because voltage was dropping. I bought new battery and alternator since both were a bit old. I've had both tested ok, battery full charge. I connect voltmeter to alt at 2000rpm - 11.65 volts. An alternator shop suggested that the volts could have been low and most likey high amps... Due to corroded cable.
Happen to know where that dang black wire would go to on a 2001 ltr?

thatsmrmastercraft
04-18-2012, 01:42 PM
Thanks Peter... How I first noticed was perfect pass rebooting! I discovered that was because voltage was dropping. I bought new battery and alternator since both were a bit old. I've had both tested ok, battery full charge. I connect voltmeter to alt at 2000rpm - 11.65 volts. An alternator shop suggested that the volts could have been low and most likey high amps... Due to corroded cable.
Happen to know where that dang black wire would go to on a 2001 ltr?

Not a clue on that black wire. You could use an ohmmeter to check to see if your alternator is grounded.

petermegan
04-19-2012, 04:37 AM
I have an LTR, I will have a play with the multimeter. Give me an hour or two.

petermegan
04-19-2012, 05:21 AM
Man do I owe you! I went to check my alternator and the black earth just fell off in my hand. Don't even think it was connected. Saved me a problem on my next outing. The black is definitely an earth. Looks as if it disappears up to the earth block at the top of the motor. The Purple is an ignition switched active and my main charge wire is Orange and thicker. Someone on here should be able to confirm that I think the Purple wire is a field wire and runs a resistance in it somewhere.(Not 100% on this). Jumper wire would be a good way of finding a wiring fault. Maybe check voltage at orange of alternator and battery and see if there is a differential.

petermegan
04-19-2012, 05:27 AM
Eric is spot on, just didn't read his post.

xbrdr1
04-19-2012, 07:26 AM
No Worries!.. just buy me a beer next time I'm down under!
OK... you answered another question I had... since it's been a week or so now that the alternator's been disconnected. That is, the black/ground goes to 'E' on the alt(Earth).

Yeah, my ground had about 3 strands of unprotected wires to the connector, with melted plastic around it of course.

I spliced my ground since like you said 'it disappears' into the harness abyss... hope to head out today and test. Will report back

Thanks guys.

JimN
04-19-2012, 08:30 AM
I have a new 55a alternator and battery for my 2001 205V. I realized an issue when voltage would slowly drop. A voltmeter test at the alternator at 2000RPM showed 11.65 volts.

I am really at a loss of what this could be? Regulator possibly? :confused:

Post a photo. If it's exactly the same as the OEM unit, the "E" terminal gets the purple wire- that's the terminal that is used to 'excite' the field coil in the alternator, since the OEM unit doesn't have a permanent magnet. If the new one does, contact the supplier to get a wiring diagram.

swatguy
04-19-2012, 09:28 AM
I am not sure if this will help you at all but my boat is 2000 X Star with Ltd engine and 70 amp alt.


I had some issues and I needed.to buy a harness to add into the wires for the new Alt. It got it from Napa. Its a plug with a yellow and red.wire that you plug into the alt into the socket. The previous owner or the previous dealership forgot to add the harness when they upgraded........who knows what happened. They guys here were a huge help.....I chased my issue and it took several phone calls different dealerships and Indmar to get the exact wiring spec in order.to get it rectified. Hope maybe this helps on the wiring side at least.
Again my info and part numbers came directly from indmar. I think its on page 3 of the thread.
http://mastercraft.com/teamtalk/showthread.php?t=44241

JimN
04-19-2012, 09:39 AM
Still haven't seen if the replacement is the same as the OEM, but replacing an alternator with something that's different from the original, instead of rebuilding that, causes this kind of problem. If it's the same, it should be as simple as making a couple of notes before the replacement is done.

petermegan
04-19-2012, 06:25 PM
I think Jim would be right in that it is dangerous to assume that 'E' designates Earth on the Alternator.

JimN
04-19-2012, 08:05 PM
I think Jim would be right in that it is dangerous to assume that 'E' designates Earth on the Alternator.

The easy way to know is by doing a continuity test from that stud to the alternator shell- if you see high resistance, it's not a ground. There's no way a ground stud would need to be insulated from the shell because it's mounted on the engine, using metal brackets, bolts and nuts.

As I posted before, the installation shouldn't be done without at least some kind of diagram if it's a different model and if I was replacing my alternator (which I have done to all of my cars when they needed it), I had the old one rebuilt or got an identical replacement. Even if higher capacity is needed, the old one can be improved to a certain extent. If someone needs more than that case will handle, a larger one can be used, but it should always come with a sheet that has a wiring diagram (or, at least the wires should be marked/tagged).

xbrdr1
04-28-2012, 06:42 AM
OK...finally got out to it. The cause was the black (earth/ground) wire from the alternator. Instead of digging through the wiring harnesses, I spliced piece about 10". Voltmeter on boat reads a bit over 14 now. Thanks all.

petermegan
04-28-2012, 07:16 AM
Goodo, I reckon that earth wire may be a common fault on these motors. Mine is micky mouse with 300hours and yet my earth wire was broken as well. Have fun.:)

thatsmrmastercraft
04-28-2012, 09:46 AM
Good to see you worked out the problem.

Helped diagnose a Tige with a sudden no-start situation once. Turned out the battery ground cable pulled out from the crimped terminal ring end where it attaches to the battery, but not far enough to see there was no contact. Too many power turns.

carlsonwa
10-08-2012, 11:17 AM
Thanks Peter... How I first noticed was perfect pass rebooting! I discovered that was because voltage was dropping. I bought new battery and alternator since both were a bit old. I've had both tested ok, battery full charge. I connect voltmeter to alt at 2000rpm - 11.65 volts. An alternator shop suggested that the volts could have been low and most likey high amps... Due to corroded cable.
Happen to know where that dang black wire would go to on a 2001 ltr?


I am experiencing this exact same issue with my alternator. My perfect Pass kept rebooting and displaying low volts, after winterizing the boat this weekend I test right on the orange wire from my alternator and I am reading 11.5 votls to the motor/mount for ground.

I pulled out the alternator and was going to have it tested, now reading below I suspect possibly my ground wire from the alternator could be the problem.

Going to have to look more into that ground wire, or make up a new jumper and test the voltage, after I have the alternator tested.

JimN
10-08-2012, 12:37 PM
I am experiencing this exact same issue with my alternator. My perfect Pass kept rebooting and displaying low volts, after winterizing the boat this weekend I test right on the orange wire from my alternator and I am reading 11.5 votls to the motor/mount for ground.

I pulled out the alternator and was going to have it tested, now reading below I suspect possibly my ground wire from the alternator could be the problem.

Going to have to look more into that ground wire, or make up a new jumper and test the voltage, after I have the alternator tested.

Check the voltage at the battery terminals, not the cable ends. You need to see exactly what's going to the battery. If you see more, you need to clean the grounding point on the engine and re-test. If it still doesn't help, make sure the ground cable doesn't add resistance by measuring at one end and comparing that reading with the voltage at the other end. You can also check voltage drop by putting the red probe at the engine ground point and the black one at the battery post. If you see voltage, you have voltage drop and it's likely that the cable needs to be replaced. DO NOT use the replacement ends with two bolts. They're meant to be a temporary fix, not permanent.