are you 100% sure the sub is wired correctly? only other thing i can think of is the deck is a dud. if it'll work proper in another car, but not in the Z, then its a deck issue.

if you have a 3.5mm jack - male RCA cable, try plugging it direct into the amp, and play something off an MP3 player, see if the sub performs like it should

 

Jalat, I will be doing the 3.5mm to rca cable with an ipod today to test it out.

But I have a feeling it may be the power run at the fuse holder, its a older wire so I am pretty sure I saw the cable being corroded at the end but I didn't really think twice about it. Now that I think it over I am thinking that may be it.

Would a corroded power wire at the fuse holder do this?

 

I bet u wired the coils out of phase

 

a corroded power wire would make the amp not work at all if anything. However I have played with some amps from back in the day and the remote wire would still trigger the power green led light, take a DMM to the power wires and see whats happening,

 

bad ground no big 3 ?

 

This is a signal issue, not power.

 

Turns out the issue was a bad ground, thanks for all your help guys.

 

I read all this way and way gonna say to improve the ground on the deck

 

curious as to where the bad ground was

 

I switched the ground from in the rear cargo area on a cargo hook bolt to the unpainted metal baffle on the stock bose system that I saw already had some things from the stock bose system grounded.