xovision touch screen lamp in wire

i would like to clarify a few things on the wire connectiosn from a cheapo xovision touch screen into a maxima. i have the metra harness and the antenna adapter. is the radio pink wire "lamp in" suppose to connect to the illumination wire harness or the dimmer wire or none. leave the pink wire alone?

there are 2 ground black wires on this radio. the braking brake brown wire needs a ground connection and the reverse gear orange wire needs a ground connection as well. can i connect all 4 wires together into one large wire and connect onto a bolt or nut behind the radio?


pink wire:
https://i384.photobucket.com/albums/oo283/joew87/xovision-pinlampinwire.jpg

maxima wiring:
https://www.the12volt.com/installbay/stereodetail/1630.html

I have never seen a reverse wire connection need a ground.  Are you sure that it is not looking for positive voltage?

i am not completely sure. i couldn't find relevant answers to 7" 2din head unit wiring from XOvision so i looked into XOvision 3" head unit for answers. XOvison's website has no manual for this XO1930 3" head unit so i couldn't look into the wiring. i got the orange wire info from walmart Q&A. it has no description for the orange wire so i don't know for sure. since this is a different head unit, i can be wrong about needing ground connection. any idea on this reverse gear orange wire?

Q&A
Q:where do I hook the single brown an the single orange wire?
1st A: I'm not looking at my manual, but I believe you are looking at the activation wires for the DVD player and the Back-up camera. In both cases, the wires need to be grounded for their circuits to work. Also remember, that the back-up camera circuit over-rides the DVD circuit.

2nd A: I can't actually remember whether it was the brown or the orange for this, but I believe the brown is for the park switch, if you don't have an automatic, tie it to ground! But beware, it allows video playback anytime the unit is on, that is almost guaranteed to be illegal! The orange is for the reverse switch I believe and switches the unit to the reversing camera if you have one installed. Check the wiring details in the manual that came with it, the colors are indicated there. (both I believe are switches to ground, not power, so don't connect these to 12v lines, it may damage the unit!)

hey iamanidiot, it is a good question about reverse gear. i think it's a trigger for the automatic reverse view camera function.

is it ok to connect all the negative wires behind the radio to the same bolt or nut?