3 plugs?

[N2scouting]

I have a 2009 3DLB. I pulled the radio and found 3 plugs plus the antenna plugged into the back of the radio. Does anyone know what the plugs goto. My new head unit does not seem to need all of these connections.

[MGargano]

I have a 2009 3DLB. I pulled the radio and found 3 plugs plus the antenna plugged into the back of the radio. Does anyone know what the plugs goto. My new head unit does not seem to need all of these connections.

One harness is for the car's four speakers, one is for all radio functions (power, lights, etc), and the third is for the auxiliary jack by the parking brake.

Your new head unit will more than likely use the first two (speaker and power, etc) and not the auxiliary port harness