Here is the long answer read through it and I will be back in a moment and give you the short one. Every thing you need to know is in the FAQ. That is where I found this.
Ken
I. Initial inspection.
A. Charging system fuse check
1. If open replace.
2. If shorts again search for short circuit.
II. Full load test. (Determines battery condition).
A. Turn ignition and high beam on while bike is not running.
B. Test battery voltage.
C. Voltage bellow 10.5V means battery needs service.
III. Charging the battery.
A. If specific gravity of any cell is less than 1.230 battery has low charge.
B. If sediments in battery are touching bottom of any plates replace the battery.
C. If specific gravity varies more than .050 then replace battery.
D. If fluid level is low add distilled water only. Don’t add too much as level may rise even more while charging.
E. Charge the batter at no more than 10 percent of its amp hour rating.
F. If battery temp. is more than 113 degrees F allow it to cool then resume charging.
G. If specific gravity of any cell will not charge above 1.230 then replace the battery.
H. Put the fully charge battery back in the bike and do the full load test again. A running RPM test cannot be done unless you have a fully charged battery. If the voltage is above 12V then you can do the RPM test.
I. Start the engine and lock the throttle when the RPM is above 4000. If the voltage is between 14V and 15V the system is fine and the battery was to blame. If not you have more work to do.
IV. If @ 4000 RPM the voltage was bellow 14V…
A. Check for problems.
1. Corroded, loose, or mismatched wires. I.e. orange and green wire plugged in to each other.
2. Modified or non-stock systems.
3. Visibly damaged wire insulation.
B. Do a system analysis resistance test.
*. NOTE 0 resistance = good wire.
*. NOTE infinite resistance while grounded to frame = good insulation. Coils will automatically have resistance.
C. Resistance testing of regulator wires.
1. While the bike is not running disconnect (-) battery lead and Black regulator wire. Check for 0 resistance between (-) battery wire and Black regulator wire.
2. Disconnect all regulator leads.
a. Test for resistance between I and F poles. 0 resistance is good. If greater than 0 clean the regulator points.
b. Test for resistance between the white wire and ground. Resistance between 4 and 8 ohms means the field coil is good.
V. Testing the stator yellow leads.
A. Test wires 1 and 2, 1 and 3, 3 and 2 for ohm readings. Less than 1 ohm means the circuit is good. Greater than 1 ohm means poor connection. Infinite resistance means that the coil has an open circuit or possibly a bad lead.
B. NOTE. For GL1000 you need to disconnect/remove the permanent magnet rotor before continuing. Set tester to insulation resistance and calibrate it to 0 to perform a wire insulation test on the stator. Ground the negative test lead and touch the other lead to each of the three stator wires. If the resistance is infinite then the coil is ok. If not then the coil is shorted to ground.
C. Test the three stator wires in the harness of the motorcycle. First disconnect the rectifier. Set the tester to resistance. 0 resistance means all three wires are fine. Greater than 0 means the wire is bad.
D. Check the wires for bad insulation. Connect the black tester lead to ground. Each wire should have infinite resistance. Greater than infinite resistance means the wire has bad insulation.
VI. Check the five leads on the rectifier.
A. To perform a forward bias test first connect the red tester lead to the green ground lead.
B. With the black tester lead test all three yellow wires.
C. Resistance must fall between 5 and 40 ohms.
D. To perform a reverse bias test connect the black tester lead to the green ground lead.
E. With the red tester lead test all three yellow wire.
F. Resistance must be greater than 2000 ohms.
G. Connect the black tester wire to the red and white rectifier lead.
H. With the red test lead test all three yellow wires.
I. All three must have between 5 and 40 ohms.
J. Connect the red test wire to the red and white rectifier lead.
K. Test all three yellow wires with the black tester lead.
L. Resistance must be greater than 2000 ohms.
VII. Testing the harness plugs and leads.
A. Test each of the plug wires in the circuit for o resistance.
B. While the battery and rectifier are disconnected test the red and white harness rectifier wire to the (+) battery lead for 0 resistance.
VIII. Regulator bench test.
A. Remove regulator cover.
B. First check the core gap to be sure it is between .6 and 1mm.
C. Next check the points gap to be sure it is between .3 and .6mm.
D. Clean the points with contact cleaner.
E. Note the 350F points gap is not adjustable.
F. Test the regulator leads by first placing paper on both sides of the points contacts.
G. Test resistance between I and F, then I and E terminals. Check you manual for model specific resistance readings.
H. Test for 0 resistance at regulator points connections.
I. While the points contact is in the upper position test between I and F.
J. While in the lower position test between F and E.
K. Note. Do not file the points or they will quickly pit when used again.
IX. Perform RPM test again. Be sure all components meet specks before going forward from here.
A. Reconnect all components but leave the regulator cover off.
B. Start the bike and lock the throttle at 4000 RPM.
C. The voltage should read between 14V and 15V.
D. If voltage is low unlock the adjuster screw nut and turn the IN. NOTE do not run the screw into the coil winding or short the screw to something else with the screwdriver.
E. If voltage is high adjust the screw OUT.
F. For the 350F bend the arm up for and increase in voltage or down to decrease.
G. Replace the cover and test the voltage again as the cover can have an affect on the field of the coil.
H. GO FOR A RIDE!
