Hi,

A 25mA drain is nothing to worry about, a radio with LCD and presets will
suck down more, seems like 70-90mA for mine.  Check the alternator, find the
fine blue wire with spade lug connector and give it a good tug.  Mine have
rusted/cracked through on 2 vans, 1 Audi, all 10 years old or more. This is
the excitation feed, and it needs to pass 7-8 volts to energize the alternator.

 If you cut back to new copper and find it has blackened, scrape it clean
and solder a new terminal on. If the solder won't take, cut the wire back a
few inches and splice in a fresh length.  Crimped connectors don't work as
well, and won't work at all well on half crudded copper. Heat shrink tubing
adds some weather proofing, but also stiffens up the connection and prevents
flexing at the lug.

HTH, Tim