Exile Mono amp swapped to bigger amp - continuous loud hum thru the subs

[hawaiianstyln]

Recently upgraded my Sub amp from an Exile Audio 2,000 watt mono amp to the beastly Rockford T2500. Zero ground noise before swapping, same RCA cables used from the Exile mono amp. As soon as the Fosgate amp kicks on the amp throws a loud continuous bass hum thru both Rockford T1D4 12’s and the digital meters on the amp max out.

The only difference is that i ran new 0guage +&- from that amp to the closest battery (5 XS power D3400’s for the house). All of my other stereo components and amps are directly wired to the next XS battery in that bank. I doubt this is a ground loop.

Am i missing something, I'm fairly decent wiring car audio for the last 30+, but this is stumping me as i know to separate wires and all grounds should go to the same location to rule out noise.  

I'm going to attempt to swap out the RCA's this weekend 

[Nitrousbird]

Have you tried swapping the Exile back in?  That might be the easiest way to see if it is an amp problem or if you need to track down another issue.

[hawaiianstyln]

6 minutes ago, Nitrousbird said:

Have you tried swapping the Exile back in?  That might be the easiest way to see if it is an amp problem or if you need to track down another issue.

I thought about that, but haven't done that yet.  I'm actually just going to pull my large amp rack out this weekend and clean up some of the wiring along with having to wire in a relay because the T2500 won't turn on with the remote wire from head unit because it has been diluted powering up the other 3 amps in the circuit.  I had to jump the 12+ from B+ to remote on the T2500 since the remote signal was weakened by being split 4 ways JUST to get it to turn on.

[hawaiianstyln]

The humming was some bad RCA’s (cheapies) and now fixed and have wired in the rockford T2500 with a relay on the remote wire and everything turns on and works nicely.  However, when i turn the volume up past 1/3rd the rockford amp freaks out and goes into yellow protect mode.  Yellow in the manual says there is a short or the ohm impedance is wrong, but i know its not i ohm’d everything out correctly.  I wanted 4ohms bridged to run this amp cooler and efficient.  Both subs ohm out to 3.9. 
checked all wiring even swapping wires out for new and still get protect mode when turning up.  Even if i unplug the speaker wires and leave the RCA, the amp still goes into protect.  Bad amp?

i plugged my Exile mono amp back in and ZERO issues, it slams.  🤷‍♂️🤬