2007 Harley Ultra over charging battery showing 17 volts Replaced Voltage regulator tested Stater all tests within specs New battery started overcharging after several days of riding

Yes the gauge could be a bit out but bear in mind that a alternator when charging will kick out around 15 v anyway so shouldn't worry too much about it.

Overcharging is normally caused by a faulty regulator. Check voltage at the battery with the bike running between 2000-3600 RPM, depending on system specs, your readings should be 14.3 to 14.7 volts. If your voltage is higher than this you have a faulty voltage regulator. Under charging can also be caused by a faulty regulator or stator/rotor/wiring.

usually it is either the regulator or stator that dies
firstly check stator...(alternator)...set multi mtr at 500ac volts
connect probes (red/blk) to both wires from stator..output voltage should read between 100 acv mid revs to 150 acv mid revs
output to battery should be 13.5v -14.75v dc...if not then regulator is RS ...I used to fit Honda regulators 30amp type with 2 red and 2 green wires ..because it is a 3 phase regulator just disconnect one yellow wire
harley regulators are of poor quality...they have no on off switch like the japanese ones ..in other words when you turn off your ignition the harley regulator is still on
hope this helps
MCS

You need to check the charging system. To do this you need to fully charge the battery and you'll need a good Digital Volt Ohm Meter. Using the meter's function selector switch, set it to DC VOLTS with a range of 20 volts or greater. Connect the red meter lead to the positive battery post and the black meter lead to the negative battery post. Start the engine and bring it to a high idle. After about a minute or so, your meter should read between 14.5 and 15.0 volts. Any lower than 14 volts, your battery will not be charged.

If you don't have the minimum voltage at the battery in the previous test, you need to check the alternator to see if it's generating sufficient voltage. You'll have to follow the wires from your voltage regulator going to the lower left front of your engine until you come to a plug. Unplug the plug and look into the engine side of it. You'll see two metal contacts in the rubber plug. This is where you are going to test the voltage from your alternator. Since you'll be testing AC voltage, it makes no difference which meter lead goes into which contact, just one lead into each contact. Set your meter's function selector switch to AC VOLTS with a 50 volt or greater range. Start the engine and bring it to a high idle. Insert one meter lead into each of the metal contacts. Do not let the leads touch each other or the engine case or ground. Your meter should read at least 25 volts.

If you do not have the 25 volts from the alternator, your stator is bad and must be replaced. If you have 25 volts or more but not the 14 volt minimum at the battery, your voltage regulator is probably bad. Make sure you voltage regulator is properly grounded. Check the condition of the wire coming from the regulator going to the battery. This wire is usually larger in diameter than the other two going to the alternator.

With a fully charged battery in the bike, connect a Digital Volt Ohm Meter to the battery, red lead to positive, black lead to negative. Set the meter's range to DC Volts, 20 volts or greater range. Start the bike. The meter should show a rapid build up to between 14.5 and 14.8 volts. If not, check the output of the alternator.

Look down near the oil filter and find the connector on the engine case where your voltage regulator plugs in. Unplug the connector and inspect both ends of it for broken or damaged connectors or wiring inside the plugs. Look down into the connector in the case and you should see two metal connections. This is what we're going to test next.

Put your DVOM meter into AC volts, 50 volts or better range. Make certain your meter is in AC volts as the voltage we'll be testing here is alternating current voltage. Start the bike up and bring it to a fast idle. Put one lead of the meter on each pin in the engine side connector. Since it's AC voltage, it makes no difference which lead goes to which pin. You should be reading at least 30 volts. If so, your regulator is probably bad. If not, your stator is the culprit.

Good Luck
Steve

unhook the nefative cable from the battery and start the bike by using another battery and then unhook the starting battery. Put a volt meter from the negative cable and then to the negative side of the battery. It should show around 14 volts if charging system is working ok.