One thing to note, most head unit wiring harnesses also have a solid blue wire. This wire is typically for power antenna or factory amplifier turn on, do not get this wire confused with the remote turn on wire with the blue/white stripe.

Where does the blue wire from the amp go?

0:335:02What is an Amplifier Remote Turn-On Wire? - YouTubeYouTubeStart of suggested clipEnd of suggested clipNow the blue with the white stripe is always typically your remote wire which is a 12-volt turn-onMoreNow the blue with the white stripe is always typically your remote wire which is a 12-volt turn-on to turn on an amplifier some radios. Only have a blue with a white wire.

Is a blue wire positive or negative?

Yellow is positive, blue is negative.