89 200q: Bum Alternator or...

["Osman Parvez" <oparvez1@Nycap.rr.com>]

Hi Folks,
    Been a long time since I've posted or been able to read posts, but I'm
back. Any way, I'll cut to the chase:

Last week my steering pump seals gave up the ship and I lost all power to
the brakes and steering. I limped to the shop and had them replace the
pump. I get a call later, telling me that the job is done but that my
battery and anti-lock brake lights aren't going off indicating a bad
alternator. 

I've checked the belt, and it is tight. Could it be: 

(1) a bad battery, and would checking the output of the alternator be
normal under a bad battery?

(2) Oil from the pump, spraying the alternator, and thereby reducing it's..
um.. efficiency?

(3) My month to pay homage to the Audi Gods? 

I don't think it's my mechanic trying to lay one past me, because I work
with him (in another department). 

Well, good to be back. Please respond ASAP. Thanks.
Osman Parvez
89 200q
170K

P.S. The only reason I'm doubting the alternator explaination (besides a
thin wallet) is I would have expected the thing to fail while it was being
run, not sitting in a parking lot. Plus, we had a fairly dramatic cold
snap.. pointing a finger at the battery.