radio installation

Greetings friends, Hope you are all enjoying the holiday season! First time poster... We've been working on a radio replacement for our 2022 Thor Windstar motorcoach for about 4 (or more?) weeks now, and after today we're really pulling our hair out. Hoping you more seasoned RV veterans can...

This 10” screen unit has four camera RCA inputs....do I simply bypass the multiplex box (w 3 inputs, sides and rear camera) that has 1 RCA out....this takes multiplex box out of the circuit....so the cameras feed directly into the receiver unit...right?……. This said, what powers the cameras?….

I’m installing a new JVC radio in a 2017 ACE...I'm wishing to use new wiring from the plug/connect (translucent clear) all the way to the JVC plug that goes into the radio....does anyone know what connector I should buy?....in an old post someone mention a Mercedes sprinter part....

We're attempting to replace the radio, whose screen took a dive, with a new JRV9000. The problem is that the JRV9000 does not appear to be receiving power. We followed the instructions (probably the first mistake!), and can't figure it out. Any help is greatly appreciated. Thank you.