[sillychilly]

hi guys my sub isnt working when i plug my mp3 player in to the usb but it works when the radio is on can anyone help ??....i neeed my sub back on lol

 

[Phatty]

sounds to me like you've wired the amp remote turn on wire to the electric aerial wire by accident.

 

[t4Chippy]

hi guys my sub isnt working when i plug my mp3 player in to the usb but it works when the radio is on can anyone help ??....i neeed my sub back on lol

As said above ^^^ remote wire to the amp should be blue T:

 

[sillychilly]

hi guys
l fited it about a year ago and its been working fine up 2 about 3 days ago

 

[sillychilly]

l dont get why it works when the radio is on

 

[Aurora]

l dont get why it works when the radio is on

What head unit?, you havent selected an audio setting under the "AUX or USB" for subwoofer defeat or switched pre-outs off?.
As some have different audio settings for each input.

 

[sillychilly]

its a sony MEX-BT3600U

 

[carl_a]

is the amp turning on or just no sound, connect your remote wire for the amp to a live and see if this works, could be faulty head unit.