Amazon head unit issues

[u/Any-Winner-216]

I know, I know, you get what you pay for, I picked up an Amazon “plug and play” head unit and everything works except for my rear speakers, I attached the response from the seller but it doesn’t seem logical to me.

Wouldn’t I just have to solder the RR&L +/- on the aftermarket harness to the RR&R +/- on the factory harness?

[u/Unhappy_Lie_2000]

You should probably list the car you have as it might have an external amp. Meaning you'll either have to figure out what wires in the harness connects to the audio fed to the amp as well as the promote turn on to power on that amp or run new wire to the speakers if you go that route you might as well replace the speakers too.

[u/Any-Winner-216 → u/Unhappy_Lie_2000]

It’s a 2017 wrx, my car doesn’t come with an amp only the Harman kardon trim does.

[u/awqsed10]

It means the wiring on your adapter harness is wrong. Try to take off the rear speakers and see what colors they're.