Stator test on harley - FLSTC Heritage Softail Classic Harley Davidson Motorcycles

To check the STATOR. Turn ignition key switch OFF, then disconnect the voltage regulator connector from alternator stator wiring. THEN connect an ohmmeter set on the RX1 scale with one lead into either of the stator sockets and the other lead to a good ground. And test for continuity - a good stator will show no continuity (0 ohms) across either stator socket - any other reading indicates a grounded stator which must be replaced. THEN remove the ground lead and insert lead it into the other stator socket - the resistance (with ohmmeter still set on the RX1 scale)should be 0.1-0.2 ohms - if the resistance is lower a stator short is indicated. Which means that the stator is damaged and must be replaced. - if the resistance is higher (OL on meter), an open is indicated and again, the stator is damaged and must be replaced. You should check socket 1 to 2 then 1 to 3 then 2 to 3. (If you only had a two wire stator you would check between wires/sockets 1 and 2).
Before testing short out the ohmmeter leads against each other and if they do not produce a reading of0 ohms subtract the reading you do get from any readings you get doing the stator checks in order to get accurate stator circuit readings, otherwise you may have out of range reading due to the internal and/or lead resistance of the ohmmeter.


You can also do an AC output test:
AC Output Check
Disconnect the voltage regulator connector from the alternator stator wiring and then connect an AC voltmeter across both stator sockets of a two wire stator, or if a three wire stator across two of the three for example 1 & 3 and then later you will repeat the test between 2 & 3 and later between 1 & 2. THEN run the engine at as close as possible in the circumstances to 2000 RPM. The AC output should be approximately 32-40 VAC, approximately 16-20VAC per 1000 RPM. If you have done a stator static test and the stator has proven to be in good mechanical condition and the AC output is below specifications, the charging problem is going to be a faulty rotor. If you have not done a static stator check yet and the AC output is less than as set out above it may be that the stator is defective and the static stator check will need to be done. While the regulator has nothing whatsoever to do with the alternator output, if the alternator output is good the regulator might be defective in either rectification or in limiting the output to the battery to under 15 VDC. If AC output is low and the stator has passed the static stator check then it is likely that the permanent magnets in the alternator rotor are weak. A permanent magnet can lose its magnetic strength if it is dropped or shocked such as letting it snap into place when being installed or possibly by use of an impact wrench to remove the compensator fastener etc.