I got this 03 Tahoe from my cousin and for about a year it's been pretty solid ,while I started upgrading the electric and I started having issues did the big power 3 which is changing all the batteries to zero off and something started draining my battery I had not found the parasitic draw yet I put some kill switches in it so it won't drain my battery and now it won't shut off....when I pull the cable off the alternator it will shut off but then when I put it back it won't start....so it turns over but just won't start and now I can pull the key out with it still running too