Good info guys, will post what I find.. I'll try and find my old headphone to RCA jack and see if I can reproduce the hum. If not, I'll get around to trying the direct wiring setup with the battery. Not much time afterwork before the sun goes down.
Appreciate the feedback gpcustom and I800C0LLECT. =)

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T66 Turbo,3" downpipes, oversized A2A,Stg3 heads/cam,hv3,built trans,bilstein struts,ssc springs,gxp brakes,pace car spoiler(1of3??),lots more.. dyno'd @ 421WHP~13lbs boost on OLD setup. New = ???

So, I figured I should come back and put a *resolved* tag on this one.

So, after months of having a hum, and trying everything under the sun..... The problem is the RCA outputs, as suspected last year. I put this to rest because the hum wasn't too bad if volume was up. As of a few weeks ago, it turned into crackling ALL the time, volume did not affect it. I figured a ground I had went bad, checked everything 20x, nothing wrong.

Decided to check RCA cables again, figuring something got pinched when I was playing with something else.. NOPE.

So, back to Google, reading nightly here and there looking for ideas. I had tried grounding RCA outputs at the amp, made things worse (last year).

Saw a thread about Pioneer units, stating I should strip back 3-4" of wire, wrap around ALL RCA outputs on my deck, and ground it to the chassis of the deck.

I just performed this, and voila, 100% clean, no noise/hum/crackle, anything. Since it worked so well, I decided I would snip my ground cable I was running to the battery from the deck and tie into the factory harness again. To my surprise, no noise, everything works perfectly.

Happy now, since I was seriously debating on getting a new deck this winter since I thought it had something to do with the chassis fan.

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T66 Turbo,3" downpipes, oversized A2A,Stg3 heads/cam,hv3,built trans,bilstein struts,ssc springs,gxp brakes,pace car spoiler(1of3??),lots more.. dyno'd @ 421WHP~13lbs boost on OLD setup. New = ???