[Mgs] Alternator, battery, fan, or normal?

[Aaron Whiteman]

I noticed tonight that the red battery light has just a hint of red as I was
driving home.

Lucas alternator was replaced by a (IIRC) 60A Bosch a few years back, and I am
using an Interstate battery I bought in 2006 or so (it sits inside during the
winter).

I have fairly bright lights (aftermarket from Daniel Stern Lighting) on
relays, I think they're rated at 55W.  I don't know if the red light goes away
when I turn them off, as I was unwilling to do so while driving at 60mph.  I
do know that if I turn off the heater fan, the red light goes dark,
disengaging the overdrive will do the same.  Using the brights doesn't seem to
make the problem worse.  Turning the stereo off doesn't make a difference
either.

The heater fan is out of a '77 MG, purely because I remember the donor car had
actual airflow when it was on, while mine didn't.

The red light is dim enough that under city lights I can't see it, it's only
on the highway where there's no street lamps that I noticed it.


My first thought was bad fan, but I also wonder if the combination of load is
just enough to overtax the alternator and the actual answer to the red light
is "this is normal, don't worry about it".  Suggestions?

--
Aaron