Repeat alternator failure.

Okay, just had my 2nd alternator fail. I will pull it next week and have it tested. If I'm lucky it's the regulator, in which case I have a spare from the last one, on which it was a bad armature. Here's hoping. I am not having luck with the electrics on this bike. Upside: I can replace the thermostat and gasket, and probably the coolant hoses this time while I'm in there. Also gave me a reason the purchase a Lithium specific battery charger/maintainer .
Just not really looking forward to this, it's a sucky job.
Oh well, such is life. Unfortunately, now I don't have a running vehicle at all. I need to get my butt in gear and swap the motor in the jeep.

What were the signs of the impending failure? Do you have a voltmeter installed?

How many mile on the first one and how many on the replacement?

ABS light flashing, then gauges dropping offline, loss of power, shutdown. Approx 70,000 on the original, 1400 on the replacement, which was a used unit. No volt meter installed, yet, it's on my list of wants....Battery is a new Lithium, just got if off the charger, tests good. Trailering the bike home tonight, plans for the weekend with the family unit, so I will drain the just filled(sigh) tank monday night and begin disassembly...
Luckily I wasn't far from home.
Hoping it's the diodes......but with my luck........

Wow, I am over 157,000 on my ST with the original alternator on the bike.

If the bike was a used Police bike, my guess would be the way the lights, horn, siren, and stuff were probably just cut off with a pair of cutters when sold.
The second problem would be purchasing ANY used electrical part and installing it on your bike.
While you have the bike apart this time, I would spend a lot of time checking every wire in the system for damage/grounding/shorting etc.
Good luck.

Ozzie said:

...1400 on the replacement, which was a used unit.

Click to expand...

Sounds like the replacement may have been bound for the can before it was installed.

These alternators are standard Denso parts on the inside and could, in theory, be serviced by any alternator shop that works on that brand. If I remember correctly, the hitch is that the attachment between the alternator and the engine isn't standard and nobody's got a rig to spin it up for testing.

Best of luck getting it fixed.

--Mark

Igofar said:

If the bike was a used Police bike, my guess would be the way the lights, horn, siren, and stuff were probably just cut off with a pair of cutters when sold.
The second problem would be purchasing ANY used electrical part and installing it on your bike.
While you have the bike apart this time, I would spend a lot of time checking every wire in the system for damage/grounding/shorting etc.
Good luck.

Click to expand...

Yup, the harnesses were butchered when all the Police stuff was removed, however, I've been through them and repaired or capped all the nasty stuff. I will hopefully start digging in tonight, here's hoping it's a mouse or something simple.....I mention mouse, because the wifes vehicle is having a mouse issue right now, caught one the other day, but have noticed more mouse droppings in the cupholder.......

Well, I sold the ST and bought a HD sportster, just got back from getting my prerequisite tattoo.


And if you believe that, I've got a bridge in Brooklyn to sell ya.

Actually, the ST is sitting near the garage, working on putting the motor back in a tahoe, just went to look at a cheap truck to hold me over while I get the gremlins excised from the ST, and find time to replace the motor in the jeep. I did find time to siphon the fuel out of the freshly filled upper tank, it went into the mower, waste not, want not.

My alternator is off and we can't find a replacement rotor through my alternator shop's sources. Any ideas?

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Dang Ozzie... sorry to hear this!

Hope you can figure it out without too much expense!