Rep Power: 0

I drive a Honda Civic EX 2000 Automatic 1.6L Coupe.
Current symptoms:
-SRS light stays on until I'm idle at a stop light
-Check engine light has been on for the longest time pulling an O2 sensor replace warning
-When I accelerate, SRS light comes on, my radio shuts off, my A/C blows stronger, and my interior lights shine brighter, all of which go back to normal once I decelerate
-All of my exterior lights work, except for the low and high beams, but interior dash will read them as on
-All interior lights are now flickering when the car is running, but do not flicker with the key turn 2/3 the way on without cranking the vehicle

Tests done so far:
-Multimeter voltage test done:
12.7-12.96 volts with car turned off
12.7 volts with car running, no accessories turned on at 0.5 rpms
18 volts @ 2000 rpms
14 volts with only high beams turned on
13.9 volts with only A/C running at max
14.03 volts only rolling down windows
14.1 volts with only aftermarket radio turned on
13.3-13.6 volts fluctuating with all accessories turned on and maxed out

-I've check my fuses, all of which (radio, srs unit, srs, low beams L/R, high beams L/R, all fuses in compartment under hood) are all good with no breaks.
-I've checked some of the visible grounds and wires, all of which don't look too dirty or damaged.

-Car will start and run normally, outside of electronics acting up, but there is also a whining high pitch noise right after the srs light comes on whenever I accelerate. Sounds kind of like a high pitched buzzing or ringing.

PLEASE HELP.

 
Rep Power: 203

Sounds like you have a short. Like a wire that's rubbing against your engine block. Since things seem OK when not running. When running the engine is probably creating enough vibration to cause the flickering. 6th gens had a known issue with this... check the wires behind the intake manifold for signs of rubbing or breakage.

 
Rep Power: 0

Okay, I'll try checking for that and get back to you.

 
Rep Power: 518

At least you did some worthwhile checking.

Should be a bad alternator.

Check for blown light bulbs and cooked battery and any other electrical damage after alternator repair.
If the noise isn't coming through the speakers.......That's probably coming from the alternator, the voltage regulator making a howling noise.