I bought a Sony cdx-c7850 from a friend. I ran me a new constant power wire from my ignition fuse & it saved everything as long as I leave the truck off for nomore than 5 mins anything after that it reset everything. I got the red wire from the unit to my pos wire, the blk wire from the unit to the neg wire & the org & wht wire & the yel wire from the unit running to a constant power wire. The only other wires I have hooked up is the FR & FL speakers. What am i doing wrong, please help