amp hum and speaker noise

I know this topic has already been posted i did a search but am looking for answers closer to what i'm looking at since i don't have much experience.

1998 eclipse GS

I have a rockford system with a 1000a2 amp and used to have a 240.4 amp next to it. i recently bought an old school 400a4 to replace the 240 and wired it all up the same as the other one that worked perfect had been wired up. The 400 was from ebay so it may be that it needs repaired but since i installed it my rear 6x9s are putting out a hum that seems to react with everything in the car (blinkers, brake lights, reverse light, etc...) the RCA was run kinda poorly because i burned through the old set and when the shop re ran them they just went straight through the center console under the armrest and carpet then to the amps in the back. (but even run like that on the old amp there way no noise) also the amp its self is putting out a hum that increasing with the engine speed and what not. I'm not sure what guage the ground wire is that they used i saw it though it wasn't anything huge probably a 8 gauge if i had to guess or maybe a four. I don't know much about the wiring as the shop did it and they did it before i owned the car but I would rather fix it than sit there all morning if it is just something like a ground loop. Am i allowed to use a bigger ground than what my power wire is. and do you think the new amp being more powerful might just require a stronger ground (Even though the 1000a2 is using same size ground)

Thanks for the help sorry if it is jumbled but trying to provide as much info as possible.

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If the cars not shaking the radio's to quiet

       Let me guess    you have a Pioneer deck?

nope kenwood deck .. yea i emailed the seller and he said he has another 400a4 and it has a small hum also but not out of the speakers just out of the amp where as mine is out of the speakers also but only the rear speakers.  (the other difference is on the old amp the speakers and RCA's were all put in on one side and the power was on the other side.) on this one the speaker wire is on the same side as the power wire so the guy at shop had to extend the wire that had already been extended so the rear speakers have to crimp connections on them where as teh front only has one. 

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If the cars not shaking the radio's to quiet

hmmmmmmmmmmmmmm

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Jared Nixon - A.K.A Jsmoke
3rd Coast Customs
Lake Charles, Louisiana

i have the same amp and with the volume all the way down it hums,and sometimes i get what sounds like alt whine in it but not in my sub amp so think these amps are just crap

ReHook up the first amp(2 ch) while using the same wiring. If it doesn't hum, the 4 ch amp is the prob. Let us know what happens.

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2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001

turned out that the amp hum was caused by rockford stupidity.... the rear RCA terminal was not grounded to the circuit board so i paid the stereo shop 50 bucks to resolder all of it and make sure the ground went through now it is quite as can be except for when i turn on the window defroster don't know bout that one but don't particularly care.... thanks for help guys

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If the cars not shaking the radio's to quiet

ill be willing to bet i have the same problem

Even though you don't care if you get sick of the defroster noise that is most likly coming from the head unit Try a different ground location or a little noise filter, might do the trick.

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Custom Audio
Lynbrook NY

ASE/MECP master certified

cool thanks

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If the cars not shaking the radio's to quiet