4 channel amp engine noise

Hi

I just re-did my audio system with all new products. I'm getting bad engine noise.I have a pioneer avic-d3 and a rockford p400.4 amp.With the infinity kappa 5x7.Installed in a 97 ford expedition

I work at a chain install shop.I've been M.E.C.P. for less than a year.This problem I'm having is just kicking my butt. I ran new Rca's down the center of my truck.Got rid of little bit of the noise.

My main issuse is: Static when the engine is off,Whine when the engine is on,and when i unplug one set of rca's I get tons of static/whine on the speakers that are still plugged in.I'm thinking bad main ground which would be ground loop? Also I get a very small poping sound when my brake lights go on?

I know your all thinking I'm mecp i should be able to figure this out,on my own.I just cant.

Thanks for your help in advance

I forgot to add I tried grounding the rca's outter loop at the amp and i get even louder buzzing

Thanks a lot for your help

You should have a test tone generator first and foremost when looking for probs

I found out I think its my rca's.I tried a different deck,the noise was still there.I unplugged the red rca from one pair and touched it to ground,thats when the noise went away.what could that be? Bad rca's picking up noise? I ran all rca's down the the center by the transmittion hump.I did remove the insulation from the rca's and grounded the shielding and it helps reduce the noise but its still there.

Thanks

Ryan

If grounding the RCA shield helps that is generally an indication of a bad ground plane in the head unit or the amp or both.  But sure, try different cables just to be sure.