bigdd

I've got a 2000 express 1500 Cargo Van. Does anyone know specifically where I should get into the reverse lights wiring up under the dash? I'm wiring up a reverse camera and a 4.3" display and obviously only want it on in reverse. I'll jump off the back up lights by the rear for the camera, but I'm more concerned with singling out the specific wire under the dash.

Thanks in advance