Just lately my radio/tape deck display numerals have started to "flash" and
do "crazy" configurations for a few seconds off and on during the day. One
day my auto door locks wouldn't work as if the battery was low. It appears
to happen less often if I don't use the air conditioning. Is my alternator
going bad and not charging the battery?

Even Stephen wrote:
> Just lately my radio/tape deck display numerals have started to "flash"
> and do "crazy" configurations for a few seconds off and on during the
> day. One day my auto door locks wouldn't work as if the battery was
> low. It appears to happen less often if I don't use the air
> conditioning. Is my alternator going bad and not charging the battery?

Its possible. It could be 100 other things, too.
How about some diagnosis? Voltage both DC and AC, current AC and DC, ohms,,
diode check, brush wear, grounds, etc.