amp, 04 f-250

I am going to install an MTX Thunderform enclosure in my F-250.  Of course I need an amp to go with it.  What I need help with is ... where do I run the blue remote wire to?  I had a system in my 04 F-250 and the fool ran the wire into the fuse box which I dont think was wise.  So do I need to pull out my radio and find the blue wire there?  Any ideas are welcome.  ThanksKing Ranch

factoryKing Ranch

Yank the factory radio and find the pink wire in the factory harness.  This wire is the radio accessory wire, and turns the radio on when you turn the key on.  This wire will test +12V with the key on and nothing with the key off.  Connect your blue remote wire to this wire.  Hope this helps!2003 Dodge Neon R/T

Alpine CDA9813, RF T2000.1bd, RF T162S, RFT142C, RF T600.4, RF T215D4

140.7 @ 28Hz