Alternator issues, Please Help

Joined
May 25, 2016
Messages
1
Location
Tempe, Az
Bike
'95 ST1100
Okay so i just got a 1995 honda st1100 Pan European with ABS and TCS. The day I got it, it road very well up and down the road. When I went home was about 20-30 miles I shut it off and let it sit for a bit and then came back to start up again but the battery seemed to be a bit weak starting up eventually causing the battery to die a bit making my lights dim trying to start it.

So next day I take left side cover off and notice my rectifier cracked a bit and fried along with the harness and wires also my starter solenoid seems a bit burnt as well along with the wires wich have some electrical tape around some of the prongs. Ill get pictures soon.

My question is, would it be my alternator that fried up my rectifier and possibly my solenoid?
Also, is there a way to re wire the harness instead of buying a whole new wire harness set for the bike?
 

kiltman

Site Supporter
Joined
Apr 27, 2013
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3,280
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68
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Stratford, Ontario Canada
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2002,ST1100ABS
STOC #
8826
Your alternator still maybe ok. You can splice into the harness and replace the bad sections of wire and put in spade connectors.
before going too far, you can check the condition of the alternator by checking the resistance of the windings at the three yellow wire connector. Do a search on the site or check a shop manual for instructions. If the alternator is ok, then order a new VRR, and mend the wires with new connectors. If the alternator is toast then prep yourself for the 40amp alt. Upgrade.
 
Joined
Apr 7, 2007
Messages
624
Location
Tacoma, wa
It's somewhat common to have a burned/melted solenoid connector on the 1100. if you don't want to buy a new wiring harness/connector, it's perfectly fine to repair it instead. I won't comment on the rectifier or alt. since I have no direct experience with those elements.
 
Joined
Jun 8, 2007
Messages
16
Location
Ravensdale, WA
It's somewhat common to have a burned/melted solenoid connector on the 1100. if you don't want to buy a new wiring harness/connector, it's perfectly fine to repair it instead. I won't comment on the rectifier or alt. since I have no direct experience with those elements.
Got a new battery after 8 years but after a few days my bike died at an intersection, battery power gone. Checked the alternator per my Clymer's manual. It doesn't charge 12V at idle, but at 5000 gets up to around 13V; I'm normally around the 2-3k mark, where the charge barely hovered around 12V. I then measured the resistance of both the stator and alternator; where one should be 0-1 ohms, mine was 1.5; where the other should be 0-4, mine was 5.5 (I'm rounding and generalizing). Now, the first step in the book for alternator is "remove the engine". That made me almost break my book in half, accompanied by choice words for Honda MC engineers. In the front of the manual is a list of what you do and don't have to remove the engine to do, and alternator is in the "not" section, but it refers to another component that is in the "yup" section. And on YouTube, it appears it can be done by taking out almost everything beHIND the engine: gas tank, fender, etc., which I assume is easier than exhaust manifolds, carbs, and all that touchy engine stuff. My question: based on the ohm readings, does that say what part is bad (stator or alternator)? And can it be repaired (like brushes), or does it HAVE to be replaced?
 

ST1100Y

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Joined
Dec 4, 2012
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4,981
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59
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Vienna, AuSTria
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ST1100Y, ST1100R
STOC #
637
The readings on the winding resistance vary with temperature and the (quality of) multimeter used...

I'd check/fix all wiring & connectors from stator to the VRR, then the VRR itself, as well the DC lines from the VRR.
Likely that there some connectors melted, possible the prongs on the VRR suffered heat damage (low voltage raises the current -> toasted connections)
 

wjbertrand

Ventura Highway
Joined
Feb 8, 2005
Messages
4,407
Location
Ventura, CA
The alternator can be removed by pulling the fuel tank and swing arm. Best solution would be to upgrade to the 40A unit as it seems to have a better reliability record than the original 28A one. The 40A unit has the regulator/rectifier built in so essentially gives you a whole new charging system.
 
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