On my way to work this morning I noticed my volt gauge below 12 volts, with the passing lamps on it is usually a little above 12 volts, I turned the lamps off and it came up a little but still below 12 volts. When I was stopped at a light it sat in the same position, when going thru the gears after the light it would shoot up to over 14 volts when the rpm's got above 3,000 but drop back down to below 12 when cruising. When I got to work, is a 60 mile one way drive, I shut the bike off, then re started it, it started fine, the battery is 2 months old, am I having a problem? The volt gauge has not ever been below 12 volts before this morning.

 

My guess is a voltage regulator. They've been a problem with late model tourers. I had to replace mine. From your description, I think that's your problem too.


..

 

I am riding a 99 EG standard so I don't think that makes it a late model lol...

 

Still sounds like the regulator though

 

late model ? it is to me...

the voltmeters usually read a little low partly because of voltage drop (through the wiring) which is higher when the spots are on- more current passing through the same wiring and switches.

you can get a true read with a "real" voltmeter attached at the battery ( or at the tender leads if you have).

the Voltmeter on my '95 FHTC read about 1.8 volts low compared to the battery when stock with headlight on, that would drop a further about .3 VDC with the spots on ( 2 x 30 w).

I later altered my wiring to remove the lighting from the factory harness, and connect the voltmeter to the battery thru a relay- readings "normalized" at about .4 VDC low, so if I looked at it from an angle it was "just right"

the regulator converts the AC from the stator to DC... it also limits the voltage to below about 14.8 volts so that the battery doesn't burn out or the light bulbs pop.

- just so the reader know what it does, since the VR is such a hot topic these days ( so signs of a bad VR are ...- passing AC voltage, allowing voltage above 14.8 DC, not producing power to the battery or draining the battery- most of these would indicate a bad diode bridge ( rectifier)

the battery not only stores a charges but also acts to regulate voltage to the bike- at most times the bike is "running" from the power stored in the battery...the charging system is re-charging the battery at a near equivalent rate ...it is not like the bike is using power directly from the charging system.




Mike

 

Thanks Mike, I am at work and have a volt meter I can put on the battery, what should I be getting at the battery with the bike running? And I do have battery tender leads on it, they were there when I bought the bike 2 months ago. I guess I am going to run up the streett and buy a tender and hook it up to the bike so I can make it home.

 

...don't worry about a tender IF your battery is "dead"- you would need a real charger 5 or 7 or 10 amp...not a .5 amp tender.
a tender will maintain a charge- not restore a charge to a dead battery.

so voltmeter at the tender leads ( or the battery if you want to pull the seat, same thing either way...)

you should see better than 11.5 volts with the bike sitting

it may dip to 9.5 or so when starting

and at idle it may be close ish to 12 or maybe a little more.

and above 3000 rpms, you should see NO MORE than 14.8 volts.

once you see that voltage is stable- turn on the spots and you'll see a drop- if you have the halogen kit the drop will be more severe--- and if you have 2 x 55 bulbs like I did, even more.
watts is a rated related to power consumption by the bulb- not how much light is produced ( lumens). You would see a similar change with the high beam - it uses about 10% more power than the low beam.

you can do all this for piece of mind- I don't think you have a problem ( easy for me to say!)


-- i gave an idea of what he VR does...here's what the stator part of the alternator does:

so inboard of the compensating sprocket is a big coil of wire- it is stationary and has 2 wires going to a plug on the left front of the motor case.

when the motor is running, the "rotor" which is attached to the crank, rotates around that coil of wire... the rotor has a bunch of magnets attached to it, as as those magnets rotate around the coil of wire- it produces AC voltage to the plug.

with the motor running you can test this by unplugging the VR and pushing the probes into the holes ( doesn't matter which one...it is AC voltage- and set the meter to AC).

correct spec is for every 1000 rpms you should see 16 to 20 VAC... so at 3000 rpms it should be producing 45 to 60 VAC...which the VR converts to DC and regulates under 14.8...excess voltage is converted to heat...which is why chrome covers for the VR are stoopid.



mike

 

ok, update, went out and checked the battery at the tender leads, sitting was 12.7, started it up and was at 12.5 at idle, still 12.5 at 3,000 rpm's.
Turned off bike, looked at the voltage regulator and connectors, pulled the wires down at the connector, started bike, volts went up to over 14, with bike running i moved the connector and volts dropped, wiggled connector and volts went back up to over 14, am going to pull connector apart and clean, When the volts jumped up to over 14 I could hear a ticking like voltage arching from around the regulator, is that a normal sound?

Thanks again Mike

 

hmmm.

check that the VR is cleanly grounded to the bike at the mounts, loosen, clean, tighten.

don't worry about making it home tonight.

Mike

 

I will clean the connector, that seems to be the problem but will go over everything tonight in the garage. I have had a sprkplug wire arc on my race car before and it sounded just like it when the volts went up on the gauge, am a rookie with HD's, this being my first touring HD. I have done nothing but play with this thing for the past 2 months and have put over 3,000 miles on it. Does anybody catch themselves just going down a road with a big grin on their face? No vehicle I have ever owned has given me as much pleasure as this thing has.