Question about 04 WJ Stereo

Hello,



I am installing a new 2 DIM aftermarket stereo into my WJ however I am seeing one thing I wanted to get clarification on.



Using the adapter harness and looking at the wiring diagram I am seeing two yellow (always on power) and two (black) ground wires coming from the WJ. My aftermarket stereo only has one ground and one always on power wire.



Is it safe for me to assume that I only need to connect one of the ground wires and one of the power wires to my aftermarket stereo? Also, is this ground actually ground or do I need to connect my aftermarket stereo to the antenna or metal body of some sort to create a ground?



Thanks!