Need Help! Front Turn Signal Access???

[MillerR]

I have a 2003 2500 HO. I had electric fold-out mirrors with anti-frost elements. I just installed aftermarket mirrors with a turn-signal in them. Where is the easiest place to tap into the front turn signal wiring, so I have turn signals in my new mirrors? I have enough wire to reach the front lights, but thought there may be something with easier access maybe near the firewall??? Any help and/or pictures would be greatly appreciated.