amp in protect mode?

[Call Me Dubstep]

My question is, are you trying to run both amps to the same subwoofer, or are your running them to different subs?

[bbeljefe]

Get the second battery grounded to the car's electrical system or get the amp's wiring off it. You can't have an amplifier that's powered from two different electrical systems.

[mikebik]

amp a is for subs amp b for speakers.... the amp's are on a distribution block from the same power source. i was using the other battery to see if it would ground but im going to find another spot to ground it.

[Broke_Audio_Addict]

You cannot run a random battery in your trunk without it being tied into your electrical system somehow and expect it to work as a ground. You have two choices either ground the amp to the chassis or tie the rear batt in with the front batt then ground off the rear batt. The rear batt will also need to be grounded to the chassis or a run from the frront battery negative to the rear one will need to be done.

[mikebik]

So a power and ground distribution block will not work if I was to use it on the battery then run both amps on it?

[Pasta Prime]

Your rear battery still has to be tied into the cars electrical.