Moved my Alpine SWR1242D and MB Quart DSC1000.1d from one car to another. (it worked fine in old car)
HU is Pioneer DEH6300UB.

I ran my wires, fused near battery, etc, but for some reason my sub won't hit.
My amp has a remote bass knob via cat5 and when I plug and unplug it I can hear the connection in my sub, but it won't hit otherwise.

I'm grounded to a piece of metal in my trunk using a self tapping screw, it's tight. I've quadruple check my speaker wire (12 guage I believe) from my amp to box, even swapping for brand new wire. I also double checked the connections inside the box.

My amp is getting power. The protect light is not on. I've adjusted all of the amp settings (even though they were setup just fine before).

I don't know where else to check, or what could be causing the failure.

Hopefully someone has some ideas.

Are your RCA signal wires to the amp all connected ?

Of course.

is your ground on a painted surface? if so you will need to sand that off.

i really don't know what else to say. you say the wiring is all hooked up properly and it worked before the switch so aside from looking it over myself i can't help you.

Pretty much this. If you say the amp isn't going into protect mode then its wired right, its just not getting the signal or pushing the signal. you sure it didn't come loose behind the HU or something?

Double checked and both ends of the RCA's are plugged in.

I sratched the metal with a pocket knife then buffered/sanded or whatever its called on metal until shiny.

I'm gonna try a different location for my ground tomorrow I guess.

After that I'm stumped. My friend has a buddy who is a head guy at best buy install, maybe I'll bring it to him to have a look at.

Did you turn on the sub out on the HU?

Yup, I even tried it on reverse just to see.

Do you have any other amps?

Nah sadly I just have this one. I might be able to borrow a shitty one from a friend to try.