alright so i have a 977 ford f250 7.3 and im trying to install this aftermarket head unit by pioneer. i think i have a correct chart for the new pioneer harness but ihave found numerous different colors of wires for the factory harness and ive tried tieing together so many different combonations but still cant get the unit to turn on when i turn the key. can anyone help?

 

most electrical issues like the one you are having can be solved with a DMM, simple matter of finding which wire has power with key on and no power with key off, that is a suitable circuit for the stereo..