87 4kcsq Power steering pump failure? (Nolan Gilliam)

[Nolan Gilliam]

Yesterday, my oxygen sensor, battery, and brake warning lights started 
fading in and out. The PSP is whining but its still functioning. ATF fluid 
is full. The warning lights fading in and out reminded me of what happened 
when my alternator when out but its been replaced as well as the voltage 
regulator. Volt meter is reading good volts, 13-14.  I really don't think 
the alternator is the culprit because electrically, the car is operating 
perfectly and idles at 950rpm steadily.  V-belts are spinning properly to 
both the alternator and the power steering pump, but there is definetly an 
audible noise, which im pretty sure is coming from the PSP, (hard to be sure 
with my head in the engine bay while its running).  Why would the Power 
steering pump trip these warning lights?  The lights illuminate
when I accelerate, not at idle.  Again, the car seems to idle and run fine 
so its probably not a vaccum leak either. Any ideas?  TIA

-Nolan