VU Meter connection

[Jdfet]

Hello everyone, newbie here with probably a silly question. I bought an analog vu meter setup from chinazon and of course the instructions are in chinglish.
I'm trying to figure out where the 12v connects to the board. The seller is usless and so I'm stuck. I'm sure you will have bunch questions for me.
I'm hooking it up to my truck audio system. I'm running a Rockford Fosgate class D monoblock to the head unit. I'm only using 2 door speakers and on sub.
What else can I tell you that would help?
Thanks!

 

[NTK]

Welcome to ASR!

I found a more descriptive picture from another seller. Is this enough or you need more help?

https://www.amazon.com/Meters-Board-Meter-Recording-Driver/dp/B08QFWBY3T

[Edit] Notice that for the input signals the connection is ground referenced. I'd recommend connecting the inputs of this gizmo to the single ended (RCA) inputs for the amp using the RCA pass-thru connections in the amp or y-splitters.

 

[Jdfet]

Yeah, I saw that but the input says 'AC', not 'DC'. That's what through me. And it supposedly takes 12-15 volts. Nothing about 9v.
I have tried to tap into the output to the front speakers but the needles peg out and the speakers cut off completely. The head unit says that there is a wiring problem, to check it then reset.

 

[NTK]

Mmmm...
According to the silk screen for the CN6 (connector 6), which I think would be more reliable than the text descriptions, input power should be AC. However, 12 VDC should probably work too as DC should pass through the diodes in the rectifier circuit, with the DC applied in the correct polarity.

I believe you should connect the inputs to your amplifier and the VU meter board in parallel, which means splitting the source (RCA) signal to go to both the amplifier and VU meter. There may be a pass-through connector on the amplifier which you may use as well.