Replacing factory JBL amp under seat

Hey guys, I have a 2011 with JBL sound (non-nav). I replaced the head unit with a Joying but unfortunately, the new head unit is not capable of adjusting the amp’s gain and the sound level is far too quiet.

Luckily, a great deal popped up on a JBL DSP/amp, so I’m going to replace the factory amp (Harmon 86820-0W622) in the same location under the passenger seat. I purchased a wiring harness to connect the speakers without cutting any of the factory wires and that’s all good.

The only issue I have now is that the factory amp has three connectors and only two are addressed with the wiring harness I purchased. There is a third, (blue) connector that carries the power, audio, and communication from the head unit. Does anyone know where I can purchase one of these connectors so I can pipe the audio and turn-on signal to the new amp without running new wires from the dash to the seat?

photo attached.

Also, any advice on running power from the rear 12v battery to under the seat?

thanks!

 

Went to my local car audio store and discovered a Metra 70-1761 plugs right into that connector. Now I’m all sorted with my new head unit and amp.