hey username.....great write up. I do have a couple questions for you though.
1) You used an external amp correct? Did you simply completely disconnect the monsoon amp....or just disconnect the grey harness?
2) Can the 12V power source in the trunk be used instead of the battery?
3) what sub/amp combo did you buy?
4) My deck (Kenwood 2019V) has RCA out/in, so how can that be used to my advantage.
1) I still use the Monsoon amp for the Monsoon system. I just use the aftermarket amp that I have hooked up for my subs.
2) I wouldn't use the 12V power source in the truck due to the fact that I would be leary of blowing some fuse or something. It is just safer to run the power wire right to the battery.
3) I have a MTX 4250D Mono-block amp with 2 10inch MTX Thunder 6000's in a sealed MTX box that was made for the subs my MTX.
4) Since you already have RCA outs on the back of your headunit, then you will not need to buy the line-out converter that I bought and splice into the grey harness.
You will not need to do that step.
All you will need to do is run an RCA cable from the back of your headunit...to your aftermarket amp that you are using to power your subs.
NOTE: make sure that you run the RCA cable and the power wire on opposite sides of the center console.