i put a 6.0 in a 1993 pace truck.everything was fine for a year or so then put a lower geared rearend in it then everything went down hill.i swapped rearends back.tcc sil.sens. is the only code showing.thats getting fixed now.but it is over chargeing and killing batterys and still runs rough.any ideas?

 

Could be the voltage regulator on the alternator, but it could indicate your battery is going bad. Have both tested for free at Autozone to determine which one is bad. Pretty simple fix.