my voltage light came on....reset the field breaker and all looked fine after that. on the return trip it did the same thing. some more details:
my battery has been showing signs of weakness. granted it is well over 6 years old but cranks the plane every time. I do have a new one waiting for the right time to install.
if you look at the attached image of my ammeter, green dot location 1 is where the needle is in cruse almost all the time (uh, except today), and very stable in that position.
voltage light came on, I cycled the field breaker. with the breaker pulled, the needle dropped down to red dot position 2.
with breaker back in, needle jumped to red dot position #3 for probably not more than a minute, maybe even less. needled stabilized back at position one for the remainder of the flight. the above steps and results from each makes sense to me.
I have one of those cigar lighter voltmeter thingamajiggys and after the breaker reset, it was fluctuating between 14.2 and 14.7, bouncing back and forth between those #s. usually it is much more stable at the lower end of 14.
the tension on the alternator belt seems normalish, maybe even slightly tighter than I remember but that could just be my brain playing games now that a blinky light came on (actually it wasn't blinking, it was on solid).
I'm going to get the specs on my voltage regulater and alternator, but other than that I'm not sure what my next steps are. I am a bumbling idiot when it comes to electrical stuff. when I was 5 I stuck a popsicle stick in an outlet and that was when I wrote off anything and everything electrical. please form replies as if you were talking to that 5 year old (pre-popsicle stick incident), because that is about where my electrical skills are up to.
thank you.