87 harley sporster charging - 2005 Harley Davidson XL 1200 C Sportster Custom

SOURCE: I have a 1993 Harley

To test your charging system. Start off with a fully charged battery in your bike. Connect a digital Volt Ohm meter across the battery. Red meter lead to positive and black meter lead to negative post. Put the meter in DC voltage 20 volt range. Start the engine and bring it to a high idle. You should read 14.5-14.8 volts.

If not unplug the regulator from the wires from stator. Set your meter to AC Volts, 50 volt range. Make sure you're in AC volt range as you'll be measuring alternating current. Start the engine and bring it to a high idle. Insert the meter probes, one into each socket of the plug. Makes no difference which lead goes where as it's Alternating Current. You should read 19-26 volts per 1000 RPM.

Now, there's a bunch of mess about how to check for open circuits or short circuits in the stator but I've found it's a waste of time. If the stator ain't making juice, who cares why, Just replace it.

If you still want a schematic, contact me off group at [email protected] and I'll scan a copy and send it to you. Make sure you tell me what you want in the e-mail as I may not remember.

Good Luck
Steve

SOURCE: 1991 harley sporster not charging, alternator?? is

Yes your Sportster has an alternator and it is replaceable. It is located behind the engine sprocket on the left side of the engine in the primary case.

First, let's make sure your alternator is bad. Using a DVOM (digital volt ohm meter) we'll test the entire system. You must have a fully charged battery in the bike to run this test. Connect the red meter lead to the positive post of your battery and the black meter lead to the negative. Put the function selector of the meter in DC VOLTS, 20 VOLTS or greater. Now, start the bike and bring the engine to a fast idle. The meter should read 14.5-15.0 volts. If not, test the alternator.

From the right side of the bike, look across the engine to the primary case just behind the rear cylinder for a wire coming out of the primary. It will have a round plug on it. Unplug the plug. Inside the plug on the primary side, you'll see two metal connectors. These are where we will test your alternator. Since we are testing AC current, it makes no difference which meter lead goes to which metal connector just make sure you're on the alternator side of the wire instead of the regulator side. Put your meter's function selector in AC VOLTS, 50 VOLTS or greater. Start the engine and bring it to high idle. Insert a meter probe into each of the metal connectors. Your meter should read 25 volts or higher.

If it does, your alternator is good and your regulator is the culprit causing your problems. The regulator is located on the frame downtubes just behind the front wheel.

If you want to repair your alternator, Disconnect the battery, drain the primary case and remove the cover. You'll have to take the compensator sprocket, the primary chain, and the clutch assembly off of the bike. Then remove the rotor and your stator is behind the rotor. Remove the stator and replace it with a new one. Reassemble the bike. If you need more specific instructions, please repost.

Good luck
Steve