Voltmeter going crazy
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Tourer
Joined: Sep 2008
Posts: 440
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From: NW Burbs of Chicago
Voltmeter going crazy
84 FLHTC. Yesterday my voltmeter starting jumping around way more than usual.
I have the same issues others have mentioned where the voltage drops when the brake lights and spots are turned on. The voltmeter always shows less than 12 volt at idle even when I test the battery output at more than 12 so the gauge is a little flaky (which others have written about so I was never concerned). I also see it jumping around between 13 and 14 on a regular basis when I'm running.
But yesterday it started flipping periodically to both ends of the range every second; the needle moving as fast as the mechanism probably allows. Then it settles down for a while. I ran about 50 miles and plugged in the trickle charger when I got home. It seemed to take much longer than usual to take the battery all the way up.
Battery load tested last year and was fine - only 2 years old. New stator and regulator last year.
I've been through the whole chargin system test routine a few times. I'm wondering if this sounds like a regulator issue; about to fail or already failed.
I have the same issues others have mentioned where the voltage drops when the brake lights and spots are turned on. The voltmeter always shows less than 12 volt at idle even when I test the battery output at more than 12 so the gauge is a little flaky (which others have written about so I was never concerned). I also see it jumping around between 13 and 14 on a regular basis when I'm running.
But yesterday it started flipping periodically to both ends of the range every second; the needle moving as fast as the mechanism probably allows. Then it settles down for a while. I ran about 50 miles and plugged in the trickle charger when I got home. It seemed to take much longer than usual to take the battery all the way up.
Battery load tested last year and was fine - only 2 years old. New stator and regulator last year.
I've been through the whole chargin system test routine a few times. I'm wondering if this sounds like a regulator issue; about to fail or already failed.
HDF Community Team
Joined: Dec 2005
Posts: 5,403
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From: NC USA
If it was cycling very regularly (every second?) I would guess the regulator. Sounds like the shunt (internal zenier diode of the regulator) is going out. But it could very easily be a short as well, anywhere from the switch to any part of each circuit.
Certainly, do the check procedure for the stator first and if the battery is up strong, unplug the regulator and go ride a few miles and see if it will duplicate the symptoms. (don't worry, they'll run a good while with no charge) If the meter stays still, plug the regulator back in and see if it starts jumping again.
Certainly, do the check procedure for the stator first and if the battery is up strong, unplug the regulator and go ride a few miles and see if it will duplicate the symptoms. (don't worry, they'll run a good while with no charge) If the meter stays still, plug the regulator back in and see if it starts jumping again.
Seasoned HDF Member
Joined: Nov 2009
Posts: 15,705
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From: Farmington ,MS
What kind? Some of the aftermarket regulators don't even make good paperweights. Bought an Accel ...lasted 2 months before it completely shorted out and left me stranded. Just FYI
Seasoned HDF Member
Joined: Aug 2007
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From: NW AR
Tom, that's why I always suggest nothing but Genuine H.D. regulators and stators. I'd put an aftermarket on one if I had to, to get me home, but never if I had a choice. It's sad, but Accel just doesn't have the reputation they used to.
So, how about this: Something is shorting, causing the voltage drop at the meter you observe. I won't go into why you see a drop at the meter, but it is a reflection on the load on the whole circuit. So, meter is jumping low. One of the breakers opens up, which causes the load to drop off and the meter to jump way up. Breaker cools off, closes, short is conducting again. Meter jumps all over the place.
The hard part is finding what circuit it is on. That's an 84, right? I'm not familiar with the 84, except that it ain't an 86. My breakers are under the faring, bolted to the top of the forks. Look at your headlight. Are the wires at the back of the connector melted? Does the headlight go off when the meter is jumping? Can you observer anything else weird when the needle is jumping? Other common failure points (as reported on the boards, y0) are the harness under the tank and an open at the harness where it goes up on the neck and flexes, and, of course, the wire running under the fender to the tail light. On a dresser, it should run along the left side along the fender strut, then jump in through the fender and just run the last few inches underneath.
So, how about this: Something is shorting, causing the voltage drop at the meter you observe. I won't go into why you see a drop at the meter, but it is a reflection on the load on the whole circuit. So, meter is jumping low. One of the breakers opens up, which causes the load to drop off and the meter to jump way up. Breaker cools off, closes, short is conducting again. Meter jumps all over the place.
The hard part is finding what circuit it is on. That's an 84, right? I'm not familiar with the 84, except that it ain't an 86. My breakers are under the faring, bolted to the top of the forks. Look at your headlight. Are the wires at the back of the connector melted? Does the headlight go off when the meter is jumping? Can you observer anything else weird when the needle is jumping? Other common failure points (as reported on the boards, y0) are the harness under the tank and an open at the harness where it goes up on the neck and flexes, and, of course, the wire running under the fender to the tail light. On a dresser, it should run along the left side along the fender strut, then jump in through the fender and just run the last few inches underneath.
Outstanding HDF Member
Joined: Oct 2007
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From: El Cajon Ca.
Before you start pulling your hair out. been there done that. Check two things. First your battery connections and second the plug on the back of the gauge. I have had both of these cause the gauge to go crazy.
HDF Community Team
Joined: Dec 2005
Posts: 5,403
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From: NC USA
Thing is, if it's a short causing a breaker to cycle, it'll only do that for a minute or so, then the breaker will be heated to a point it will stay "open" for a much longer period of time.
And this is a bit out there, but once the Wyoming wind whipped my turn signal flasher(it was loose) under the dash till it finally beat the cover off it and shorted against the fork. The voltmeter was cycling like a turn signal was on but with a greater current draw / lower volt reading like 10 to 13.5 to 10 to 13.5 etc...
So good luck with your "ghost" wulffe, and do let us know what you find.
And this is a bit out there, but once the Wyoming wind whipped my turn signal flasher(it was loose) under the dash till it finally beat the cover off it and shorted against the fork. The voltmeter was cycling like a turn signal was on but with a greater current draw / lower volt reading like 10 to 13.5 to 10 to 13.5 etc...
So good luck with your "ghost" wulffe, and do let us know what you find.
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Joined: Jul 2007
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From: Connecticut
Smell like a short as t150vej suggested but it's hard to be sure without seeing it up close and personal like. I'd like to add a suggestion that you stick a test voltmeter directly across the battery and see if it tracks the voltmeter in the fairing. I've seen analog voltmeters that are grossly under-damped and will thrash around violently when small step changes and voltages occur.
Q for Dr. Hess - How about Cycle Electric brand? Reason I as is that sooner or later the stator in my 97 FLHTCI is bound to burn up / crap out and it was my impression that their products were top notch.
Q for Dr. Hess - How about Cycle Electric brand? Reason I as is that sooner or later the stator in my 97 FLHTCI is bound to burn up / crap out and it was my impression that their products were top notch.
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Joined: Aug 2007
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From: NW AR
A for Pat - Well, I'm sure there is good stuff out there, but I don't buy enough Harley parts (fortunately) to know what is good and what is junk. I know that a Genuine H.D. part is probably as good as the original part was, so that's what I stick with whenever possible. Especially misson critical parts like the electrical system. And, with that, I'm also concerned with being able to go into any dealer across the country and buy a replacement on the spot, putting it on in the parking lot and riding on. I've had to do that before, once at a KC dealer on the way home, and that's important to me. (The yuppies at the free-hotdog tent kinda looked on in awe and disbelief as I swapped out a part in the driveway.) I hear there is a nice 3 phase system out there that has more amps, is reliable, farts louder and jumps higher, but can you get a regulator at any of a thousand shops across the country if you're stuck? That's my concern. If I just rode the bike around town or trailered it (GOD HELP ME), I might not worry about that. It's just my philosophy on it.
