Earlier this month when I had the A/C running, the battery light came on. I switched off the A/C and it has been fine ever since, but I have not run the A/C at all. Does this indicate a weak alternator or could there be something else going on?
clean your battery connections and get some stuff at the auto parts store to neutralize/clean off any acid. Check your grounds too off the negative cable.
When you reattach the connections on the battery, then try to turn the battery clamps sideways, it should be nice and TIGHT
How much does all this cost [except for the can of cleaner]? $0.00
The alternator pigtail is another source of problems and you will have to do a search on that
Go on YouTube,, search terms: alternator, voltmeter [or multimeter], battery
There you will find a variety of videos that describe how to use a voltmeter to check out your alternator.