I've got an electrical problem I started to troubleshoot and have a few questions before I get back at it this afternoon.

Is the draw of a bad regulator a constant, or can it be variable?
Is there any system, or what could be the issue, of a constant 1.36v draw....with all fuses removed?

So far, I leaning towards the regulator going bad.

Thanks for any insight you can provide.

I know background info helps, so here it is:
-01 FXDWG with ~15k miles ( I know...low miles, but I got injured in AF and ride very little, but still take a day ride at least once a year.

Conditions:
-I got stuck in traffic last summer on a hot day and bike died with a dead battery....dies as I made it to an exit to get off road and wouldn't start. The batt tested bad. I figured I killed it in the heat. Everything worked fine when I used the Sporty batt to start it and go around the block.
-Replaced batt before taking a ride last week. After a 1.5hr ride, it wouldn't start. Just clicked with a low battery.
-It's not charging enough and/or has a drain.

Troubleshooting done so far:
-Charged batt and it holds. OK
-Check regulator for grounding from regulator to frame. OK
-Disconnected regulator from stator wires and checked for continuity between stator pins. OK at 1.2x
-Checked for draw to isolate system. I disconnected the battery on negative side and used a multimeter to watch for voltage between negative cable and negative post on frame. Reading was 12.xx. Removed fuses until there was a change. Security fuse removal dropped it to 1.36V. That fuse was the only one to make a change.
-I then removed all fuses. I still got a 1.36V reading!

Next planned steps:
-Check charging output. Will check with bike running and multimeter on stator pins @ regulator connector. Planned for this afternoon.

 

Well first off, a draw isn't measured in volts, it's measured in amps. Hook an ammeter up in series on the ground to the battery (so disconnect the ground, attach one meter lead to the battery ground post, and the other lead to the ground cable). While watching the draw, disconnect the regulator and see if the draw goes away. If your charging voltage is lower than 14.6, I'd replace the regulator and go from there since they often will cause a draw. A bad battery can kill the regulator, and vice versa. Don't forget to test the stator too. This is normally a relatively simple issue to diagnose, so be patient, and test each component, and you will have it diagnosed in no time. If I remember correctly, you can test regulators off the bike/disconnected with an ohm meter. Also check your connectors as they will sometimes burn/melt due to a bad regulator. Hope this helps, and keep us updated.

 

Also do a diagnostic on the stator. There is a DIY in this forum for electrical charging tests. A bad stator will take out a reg. and battery.

 

Yes, that is the place to start, at the source. Check AC output, opens, shorts, grounds, then plug reg back in, check it for continuity to ground, then check B+ voltage at battery and amperage output. As mentioned previously, draw is measured in Amps. You should find the issue if you start at the start and work your way to the batt.

 

You don't normally see a volt draw. To me, you hook you volt/ohm/amp meter in line with the battery cable and check for amp draw. It's not in volts. 1.5 mamp is fine. The alarm, speedometer, ECM all draw a small amount. Quoteing off top of my head. Newer alarms is very little.

When you first hook up, you will see a large spike. Then it trims off to above. That is the alarm checking and then going back into monitor.

If it's a lot more, and all fuses are out, Unhook the alternator rotor. There should be proper resistance across all the possible connection of the three wires. There should be no leaks on any wire to frame ground.

Use my electric 101 to check your charge output.

Rev. 12-03-16
Some electrical 101 and a little more..

Remember, the best made brand new battery that has been on a maintenance charger for 3 days that has a loose or bad connection is no better then a boat anchor with a loose rope. The connection can get loose after one ride if the battery is not anchored and the wires are short and get tugged in a direction that can unscrew the bolts.

After a good 24+ hour maintenance low amperage charge, with the charge light in the solid green and the battery has set about 24 hours off charge, voltage should be about 12.8 volts.
You can speed up this process by turning on the ignition key (headlight comes on) for ~3 seconds and then switch it back off. This is enough of a load to bleed off the excess residual charge from the charger and then you can measure the battery voltage.

12.8 = full charged
12.6 = 75% charged
12.3 = 50% charged (Lot of new modern cars with system protection will not even click at this point but will have good headlight beams showing)
12.0 =25% charged

Always check both the terminals at the battery lead and also at the terminal on the wire. That helps to verify connection. With a DC volt meter (one that has a feature to lock high and low reading is best) hooked across the battery terminals and reading 12.8 or so, crank motor and while its cranking it should not drop below about 9.6 volts and as soon as it starts and throttled up to 2000 rpm, voltage should read around 14.8 volts. The 2000 rpm is the bench mark standard. Ignore idle output. Ignore output above 2000rpm unless it exceeds 14.9 volts. That is a sure indication that regulator is bad.

The crank check shows a rough check of the reserve amperage capacity of the battery while cranking with a 150-200 amp load on it. The 14.8 shows a good alternator and if you leave it on a while as the regulatory will drop the voltage a little showing itself working. However, with the lights and stuff always on, it will never drop back much. If you have a lot of options, most modern bikes will not show 14.8 charging volts at idle but stock newer bikes will be close. Older bikes with lower amperage output not so much. However, 2000 rpm is the bench mark for the standard 14.8 volts.

If you think battery is good and something is draining it sitting, now would be a good time to check for drain problems. Go to Harbor Freight and get you a AC/DC meter for under $25 or so. http://www.harborfreight.com/ac-dc-d...ter-37772.html Make sure it has DC amps draw, DC voltage, resistance and AC voltage. Key off. Remove the negative cable off the battery. Set meter on DC amps. Hook the meter lead to cable and the other to battery. !!Key off..do not turn on!! Ignore that first draw as the alarm trims back and stuff charges for 1 minute. Now,how many milliamps (mA) is it drawing? It should be no more then 6 mA which is the ECM (1), speedometer (1), tac,TSSM (1),HFSM (1) and voltage regulator (1)

When a battery wears out, a good charge will show fairly good voltage, but the battery can still have very low amperage capacity which will show in the crude crank test above, but it really should be checked after a good charge by removing it from bike and getting a free check at a place like AutoZone that has a fancy load meter check that gives you a print out of the battery health. Battery MUST BE CHARGED to check it. Be sure they set their meter to correct cold cranking amperage stated on the battery. Never charge the AGM absorbed glass mat battery with a regular car battery charger unless it is a newer one that says safe with this type of battery. Also, by taking battery out you now know you have good connections. Vibration tends to loosen the connections or a little corrosion will prevent charging or cause starting problems. Be forwarned, these checks quite often are incorrect due to the low amperage of these small batteries and junk checking equipment. If bike is charging , no load on battery when key is off and you are still having problems…REPLACE THE BATTERY. If battery is more then 3-4 years old.. REPLACE THE BATTERY.

Using the maintenance charger can get more years from a battery but be careful here. You do not want the last start 5 miles from home. If it still grunts when you first hit starter or kicks back with a bang, replace it. After a few years, charge and pull battery and have it checked for cold cranking amperage ever spring. Even then, if it grunts most ever start, I would replace it. Most battery checkers at AutoZone and places like that do not do really well on the low amperage setting on small batteries. Not sure why but they tend to say they are OK when they are weak. If they have one that fits your bike, Wal-Mart's AGM absorbed glass mat battery is just as good as any for one third to half the money of a Harley Battery. Do not put an old fashion one with vent tubes on a modern TC Harley. Do not jump, push start or run bike with a half dead battery except in a real emergency. If a bike battery is down and you jump it, throwing all that amps to it from a big car battery especially one that is running can wreck a bike regulator or charging system. Charging a worn out battery can kill alternator stator or the voltage regulator or both. Probably ending in a big dollar repair in parts alone.

It is also a good idea to always check your battery at 2000 RPM with your meter set to AC. If by chance, the regulator goes bad, sometimes it will let AC come thru. That is a sure sign of a bad regulator. Older 2 wire stators have a single phase output while the newer stators with 3 wires have a 3 phase output. The 3 phase system provides a more consistent and higher current output to the voltage regulator. The voltage regulator takes the AC from the alternator, rectifies it to DC and limits the voltage level to the battery depending on the voltage reading it gets back from the battery.

Also remember, when starting a Harley, hit the starter and hold it in till it is firing on both cylinders and running before letting up. If you let up before it’s running, quiet often, it actually take an FI motor longer to start. There is a fraction of a second more for a long stroke Harley then a multi-cylinder car for it to get going. If you do not do this, it will kick back with a bang, sneeze thru the intake or crank a lot longer the second time or shame on you the third time. Also, if you have a habit of doing this, the starter solenoid switch contact will only have half the life it could. You cannot hurt the starter. The starter gear has a sprag clutch. There are drive pins in it that as the gas motor catches and run, it outruns the starter motor drive and disengages it from the electric motor. If you hold it in a little too long and listen carefully, you will hear the sprag clutch run up the ramps and slip. Makes a sizzle hum. This will show you your starter sprag clutch is OK.