Backup camera wiring - Backup light ?

[CZ Eddie]

Hi, I'm going to install a license plate holder style backup camera into my friend's 2001 extended cab Silverado tomorrow (three door).
Can someone tell me where to get the backup light power from?

So the camera will have RCA, ground and power.
And the power needs to be connected so it gets turned on whenever the truck gets put into reverse.
So I'm guessing that'll be the backup lights but I'm not sure where the wiring is located or which color wire I should tap into.

Can anyone help?

Oh, and what length RCA wire do you think I'll need to go from the license plate up to the in-dash stereo? It's not a big deal, I'll find out tomorrow and have plenty

[Kudzupatch]

Backup light circuit is what most people use.