Wiring factory tailgate handle backup camera to indash Pioneer 4500 screen.

Hey guys,

Was hoping someone could shed some light onto this issue for me. My 2009 Access Cab tacoma came with the factory backup camera in the handle and the wiring harness, it did not come with the mirror with the screen. I bought it used. It has the plug in the headliner where it would plug into the lcd screen mirror. I have tried hooking it up to my aftermarket in dash screen. I used a step down 12-24V to 5V as a precaution. I have hooked up the indash Pioneer 4500 correctly and everything works and I am getting a black screen when I put it in reverse. I have tried tapping into the wires on each side of the plug going to the plug in the headliner above where the review mirror would go. Can someone point me in the right direction? I was hoping this was plug n' play, but I am finding out that is not the case. Is there anything I need to connect between the tailgate camera and the fusebox? I appreciate everyones help.

-Fishman