Is there an aux output on my radio
 

I have an 05 FX4 Screw with 6 disc cd / factory sub. Does anyone know if there is an aux output in the back of the radio or do I need to take the radio out?

no only speaker out put.and sub out.

you could try finding an fm modulator like what they use to direct pluggin external sat. radio pluggins... go to any best buy and they might be able to add one on to factory radio for you.

Your model won't have actual RCAs in back, but it should have the plugin port where you can add an adapter:
https://www.f150forum.com/f4/aux-whe...03/#post266467