generator light stays on

[Omarttentmaker]

Got a '69 FLH with an electrical gremlin. Just recently the genny light stayed on with the bike running. Did the 2 tests that I could perform from the manual for checking a grounded light wire and amperage from the generator. Things seemed OK, but I am still in the dark. Put a new voltage regulator on with no positive result. I used the ammeter that is installed on the bike (Stuart-Warner, mounted on the handlebar crossbar) to check genny amperage. 2 things that I noticed didn't set well with me. First, with the gage disconnected from the wiring harness, the starter doesn't work. I'm trying to track down the wiring, but wondering if this is correct. Secondly, after tying the 2 wires that go to the gage together so the starter would work, I attached jumpers from the leads on the genny ("A" and "F") to the gage and fired the bike up. The ammeter needle moved, but in the wrong direction (neg. instead of pos.) Pretty sure I had the gage hooked up correctly. All I can check now is to make sure that the wires from the regulator field and armature terminals are not grounding against the bike somewhere. I would think that the wires hooked to the "BAT" terminal are OK, because if they were touching anywhere I'd get an instant short. Anybody with any insight into this ?

[Architect]

Have you tried polarizing the generator???

[Lyle Manheimer]

An ammeter is always connected in line in a circuit, usually in the positive lead of a DC circuit. Yours must be connected somewhere in the starting circuit which would account for the starting problem. A voltmeter is always connected across the circuit positive to negative. Ammeters are usually marked with a + and a - sign. The + goes toward the source the - should be connected to the load side. So if you want to read amps, current, or if you like load in a circuit you must connect it in line. You did not do that with your test. I think you are trying to read voltage coming from the generator. That would be done by connecting a voltmeter plus to the field terminal and the negative to a good ground or the negative battery terminal. With the bike running and the circuit loaded, lights on, you will read unregulated circuit voltage probably in excess of 15 volts. I know the manual talks about carbon pile testing but that is nothing more than placing a load in the circuit which you are doing with the lights on.
I hope what you did did not damage the generator!! In any event what Arch said is true and new voltage regulators must be flashed or polarized as well.

[Omarttentmaker]

Here's a pic of the diagram I used to check the amperage. And yes, I did flash the field coils before I hooked this up. Also flashed them after I installed the new regulator 20191030_073514.jpg.
I also did not leave the ground wire attached for any length of time, but touched it off to the engine case intermittently as was recommended in the instructions.

[Lyle Manheimer]

Ok that is straight from the manual. The original wires were lifted at the generator and jumpers were used for the ammeter and the field terminal. Double check the ammeter connection. The + side goes toward the generator a terminal and the- toward the voltage regulator. When you short the f terminal to ground momentarily you simulate a high load and the ammeter should read on the charge side, if it does not you have a bad generator. You stated twice you flashed, polarized the field coils. There is also a procedure for polarizing the voltage regulator, either in the manual or enclosed with the new regulator.
A quality rebuilt generator with warranty is a good choice as rebuilders use better materials than new, they do not want it coming back.