[V6-12v] no blower, sunroof, or turn signals

[Kent McLean]

Yesterday, I drove my my '94 100 S with V6, FWD, and automatic,
to a Fourth of July party, and had no problems -- AC and sunroof
worked fine. After the party, I started the car and pushed the AC
button (manual HVAC, not the automatic CC) and turned the fan to
3 -- but got no air from the vents, no sound from the blower.
Grrr.  I turned the knob to open the sunroof and -- nothing,
sunroof didn't move, motor made no sound.  GRRrrrrrr.  I noticed
a few more things electrical were not working, like the turn
signals. I checked the owners manual to find those items are
controlled by fuses 11 and 13.  When we got to our destination,
I checked those fuses and they were fine (not blown).  Hmmmm.
After the party, I got back in the car and magically the blower
fan was working, the sunroof was working, and the turn signals
were back. On a may-be-related note, the automatic transmission
screeched loudly when shifting from park through reverse to
drive. Once it drive, it behaved normally. It made no noise
after the AC and sunroof started working again.

Where does one start debugging flaky electrics?

-- 
Kent McLean
'94 Audi 100 S Avant, 12v FWD automatic
'89 Audi 200 TQ, "Bad Puppy"