So I was given a used VAFC. I want to make sure it works before I install it. If I connect the red and black wire to 12v, the button back lights come on, but the screen does not turn on.

What is the best way to see if this thing works?

 

Should I just hook up the other wires to 12v?

 

It has two ground wires im pretty sure, dont just hook up all the wires to 12v. Look at the wiring diagram, its not that hard.

 

The instructions online are crap. But yes it has two grounds and two powers. I was going to hook those to 12v. Not all the wires...

 

I hooked up the four wires and the unit does work. The only issue I can find is when I initialize it, it does not clear the settings. Any idea?