I am trying to install an amp and subwoofer, I just removed the blue wiring harness from the stock BOSE amp. Do I just remove the +/- Left and Right Rear speaker wires and convert to RCA or do I still keep it hooked up to the wiring harness and then splice it so I have it still connected to harness but also connected to the RCAs?

Also I have an RCA wire that came with my amp kit, it has RCAs on both sides, can I just cut off the RCAs from one end and splice the ends together with the wires I spliced from the harness?

 

Yes, convert to RCA and yes, you can cut them. if you're still using the stock headunit though, you're still likely to get bad sound due to the balanced signal that the Bose headunit puts out.

 

You will need to splice it so your rear speakers will still work, unless you dont want them to. You will also need to splice for the remote turn on. And I believe you can just cut off the RCA plugs on one side.

 

There's quite a few JL audio amps that have input signal sensing, so a remote turn on isn't necessary.