i have ordered 2 different harnesses and still dont think i got the correct one.got the matra 70-5517 ford pre amp plug and the 70-1771 that was also listed for the explorer. but when i pulled out my old pioneer unit i saw there is no amp plug on the original harness. it came factory with the amp and sub. has anyone else upgraded their pioneer edition ford explorer sport trac. please let me know as i would love to be able to have this installed soon