ST1300: What are the signs of a failing alternator?

See... your voltages are about 1.0v more than mine. This has me concerned

STPs probably put more stress on alternators than regular bikes, just a gut feel.
 
SupraSabre said:
The only alternator failure I have had was catastrophic. I was merrily riding down the freeway when my tach and speedo both quit. So I headed to the first offramp. By the time I got to the side of the offramp, the bike died. It had drained the battery! You might want to check your connections too, just to make sure you have good solid connections going to the battery!
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I just had that happen today....how much of a pain is it going to be to swap out the alternator? Figured I might as well replace all my coolant hoses and clamps while I'm in there.....
 
Hueyf4i said:
I just had that happen today....how much of a pain is it going to be to swap out the alternator? Figured I might as well replace all my coolant hoses and clamps while I'm in there.....
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It is not too bad getting in there, just take your time and you will have it done. You are right about changing the hoses at the same time, don't forget the "O" rings under the front of the motor where the small hoses connect. You should also get a new thermostat and "O" ring for the water pump while you are at it.
 
970mike said:
It is not too bad getting in there, just take your time and you will have it done. You are right about changing the hoses at the same time, don't forget the "O" rings under the front of the motor where the small hoses connect. You should also get a new thermostat and "O" ring for the water pump while you are at it.
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Is there an alternative to buying the $800+ new oem replacement?
 
put your volt meter on ac voltage across the battery terminals anything over 70 millivolts means diode/rectifier is failing.
 
ST-Traveler said:
I was wondering about this myself, On the way home from the UP of Michigan on I-75. I was traveling at a constant speed and my volt meter was dancing between 13.7 and 14.1 up and down while maintaining a constant speed of around 70 mph. (I put a new OEM alternator in this past January 2019). I never noticed this "dancing" of the voltmeter under a constant speed before. At first I thought my new alternator was failing, but then it went to 14.1 volts and stayed there for most of the rest of the ride. Then I was recalling that when the cooling fans kick on the voltage would drop like that- I just never noticed it under constant speed before?
Would the cooling fans kick on while under way traveling around 70 mph?
Something (phantom) was putting a draw on my electrical system while at a constant speed that I have never seen before. My bike is basically stock electrical - except for GPS, battery tender,voltmeter, and a charging port in my top case. I have nothing else wired to it. I did have my phone plugged into the top case charging port but I don't think it would have made the voltmeter dance like that.
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if your cooling fans kick on while at 70mph you have a cooling system problem.
 
Hueyf4i said:
Is there an alternative to buying the $800+ new oem replacement?
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When mine failed a local auto electric shop could have rebuilt it ( the rotor had gone open circuit ) but had no way to bench test it and warranty their work because of the ST's gear drive vs the more common belt drive. The bike had 116,000 miles IIRC. Replacement parts were available but when I added everything up it wasn't a whole lot more for a new one with Honda warranty and piece of mind. The alternator was about $510 at the time in 2013. The job wasn't particular difficult overall but it was hard to pop the throttle bodies off. It took me about 10 hours working at a slow pace.

I detailed the R & R of the alternator and all of the cooling system hoses:

ST1300 charge system failure | ST1300 Related

Well, I guess I will get the chance to go in as deep as the alternator. Saturday 2/2/13 I was halfway from nowhere out in the middle of the Okefeenoke Swamp when I lost electrical power and the engine quit while riding east on GA 94. Roadside triage presented a dead battery - I had dim lights...
www.st-owners.com www.st-owners.com

Help removing ST1300 throttle bodies | ST1300 Related

With an apparent alternator failure I am at the point of removing the throttle bodies. I haven't done this before and am following the Service Manual procedure and came to the computer after completing access to them but not removed them yet. Are there any shortcuts here like not having to...
www.st-owners.com www.st-owners.com
 
@Hueyf4i Up for a road trip?

Free - FREE ST1300 Alternator - NOT MINE! | Free

Found this poking around on Craigslist, if your near Burlington, NC! ALTERNATOR HAD 70K ON IT WHEN IT WAS CHANGED OUT. I RECEIVED WHEN I BOUGHT THE BIKE WITH 83K MILES ON IT. Free. To who ever wants it. https://greensboro.craigslist.org/mpo/d/burlington-alternator-for-05-honda/7498192221.html
www.st-owners.com www.st-owners.com

Josh
 
Josh_ST said:
@Hueyf4i Up for a road trip?

Free - FREE ST1300 Alternator - NOT MINE! | Free

Found this poking around on Craigslist, if your near Burlington, NC! ALTERNATOR HAD 70K ON IT WHEN IT WAS CHANGED OUT. I RECEIVED WHEN I BOUGHT THE BIKE WITH 83K MILES ON IT. Free. To who ever wants it. https://greensboro.craigslist.org/mpo/d/burlington-alternator-for-05-honda/7498192221.html
www.st-owners.com www.st-owners.com

Josh
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9 hour round trip in my truck might cost me as much as a brand new alternator....lol
 
USPS Flat rate shipping box....offer to pay shipping.
I just wonder why someone would want an alternator that was taken out and replaced by another.
Why would you want a broken alternator?
:rofl1:
 
Igofar said:
USPS Flat rate shipping box....offer to pay shipping.
I just wonder why someone would want an alternator that was taken out and replaced by another.
Why would you want a broken alternator?
:rofl1:
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I'd rather get a new one and know that it will work...for at least another 116,000 miles. Even if does hurt
 
Hueyf4i said:
#4 is all I should need, right?
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You might consider the sub harness part #21. It's very hot in the vee and the wire insulation of this harness that connects the alternator to the main wiring harness was sort of age and heat hardened. I did not replace mine however and sort of wondered about now and then until I sold the bike 60 something thousand miles later.
 
dduelin said:
You might consider the sub harness part #21. It's very hot in the vee and the wire insulation of this harness that connects the alternator to the main wiring harness was sort of age and heat hardened. I did not replace mine however and sort of wondered about now and then until I sold the bike 60 something thousand miles later.
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Might as well. I'm already planning on replacing the coolant lines, thermostat, abd clamps since I'll already have it all opened up.....
 
@Jim Van bought and installed a much cheaper new made-in-China alternator in his ST1100. He reported no problems with it after 15,000 miles. Maybe he can provide an update.

Jim was was given a link to the vendor by @kiltman. Maybe he can provide it again. Maybe that same company makes a much cheaper alternator for the ST1300 as well.
 
Hueyf4i said:
#4 is all I should need, right?
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If you go that route, you may need #21 and #23 also.
I'd hate to find out you had a damaged o-ring and have to redo everything.
Your sub harness may also be damaged (cooked or rodent damage).
Most shops refuse to replace an alternator unless you purchase both the sub wire harness in that area, as they are always found cooked by heat.
 
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