1994 Oldsmobile Bravada bravada

I got this thing n it started runing like crap n i parked n drove my other car n i went to start it n it wouldnt start wene u turn the ignition to start the wires the hot wire from the alternator gets cherry red n starts smoking in a matter of seconds n we put a new starter on it n its good we had it checked i also had the alternator tested in its good i think there is a short somewere any sugestions to were to start first please n thanks