On Tue, 04 Aug 2015 18:10:51 -0600, Tony Hwang
wrote:

Snuffy "Hub Cap" McKinney wrote:
This just started.... or at least I just noticed it. With the headlights on dim and engine warmed up and idling, the brightness cycles from normal to slightly dim. Cycle time is around a second. When I rev the engine slightly, they return to normal steady brightness.

When running with or without lights, the ammeter is just right of center, slightly charging, in the normal position.

I don't suspect a connection -- within the last 2 months, I removed and cleaned all the battery connections, including regulator and other parts when I was fixing a grounding issue.

Battery cranks start just fine. No other indications of failing battery.

Thanks folks,

Snuffy



Alternator generates AC current which is rectifiev by diodes bank.
Some times one diode goes bad(opens or short)
That is DEFINITELY not the issue, as the alternator is a (generally
anyway) 12 pole 3 phase devive, and is geares about 2:1 from the
crank, so at 500RPM idle would be turning about 1000RPM, making about
60Hz power (if my math is anywhere close to correct) so any cycling
would be in the 1/60th second range -a very high frequency flicker,
not a surge with a 1 second period.