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Alternator returns from dead


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#1 sailSAK

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Posted 16 July 2012 - 02:49 AM

After my top end rebuild my alternator refused to come back to life. Won't put out anything and tach doesn't work. I accepted the fact that it must have fried somehow and ordered another new one. Really really wanted to go out this weekend, so I borrowed a Honda 2000 gen and took off with the dead alt. About 3 hours of motoring I needed to adjust my new dripless shaft seal so it wouldn't drip at higher RPM. After this I did something I have only done on a few occasions and ramped up to WOT to test the seal. All of a sudden the tach needle shot up to 3200RPM and the volts jumped up to 14 (from pretty dead). So my alternator is working again??? I combined the house bank and watched charging amps jump right up to about 55amps. Its working!!!! Checked the tach against a laser tach and it is dead on.
Pull in, dock the boat, restart the engine and nothing. Reved it a few times and the alternator refuses to kick in.
WTF???
Alternator is a Valeo A13N 50 amp, internal regulator.

#2 JimL

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Posted 16 July 2012 - 04:37 AM

Check excite voltage connection & wiring (which I am sure you have done) and regulator.
I guess the next step is unbolt the beast and get it checked out at an Auto Electrician who would spin it up and check output.
I had similar drama with my Bosch 50 amp job and it was crook wiring/connections.
I then fitted an external smart regulator.
Good luck.
Cheers
Jim B)

#3 Fleetwood

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Posted 16 July 2012 - 07:57 AM

+1
90% of (my) engine problems are due to poor electrical connections. (The rest are due to other electrical problems!)
Sounds like a poor connection that managed to temporarily go good due to vibration or it heating up when you ramped up the engine.

#4 stranded

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Posted 16 July 2012 - 08:20 AM

......or when the voltage got up enough.

#5 sailSAK

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Posted 24 July 2012 - 01:25 AM

I'm posting this with the thought that it may save others some loot.

Alternator Light... gotta have it. I replaced mine with LED's as part of my instrument sprucing up.. well that doesn't work. I feel like a dumbass now, but hey, at least I have a spare alternator. That was on my list <_<

#6 JimL

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Posted 24 July 2012 - 04:19 AM

I'm posting this with the thought that it may save others some loot.

Alternator Light... gotta have it. I replaced mine with LED's as part of my instrument sprucing up.. well that doesn't work. I feel like a dumbass now, but hey, at least I have a spare alternator. That was on my list <_<


Slow, There is a simple circuit I found (somewhere, just can't locate it at present) that you can use a LED for the alternator light.

I am sure someone else around here knows of it or may have it.

When (and if) I find it I will post it.

Cheers,

Jim.B)

#7 sailSAK

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Posted 24 July 2012 - 02:39 PM


I'm posting this with the thought that it may save others some loot.

Alternator Light... gotta have it. I replaced mine with LED's as part of my instrument sprucing up.. well that doesn't work. I feel like a dumbass now, but hey, at least I have a spare alternator. That was on my list <_<


Slow, There is a simple circuit I found (somewhere, just can't locate it at present) that you can use a LED for the alternator light.

I am sure someone else around here knows of it or may have it.

When (and if) I find it I will post it.

Cheers,

Jim.B)


I took the illumination bulb from one of my old gauges and just wired it in parallel with the LED. Works fine from what I can tell.




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