1998 GMC Suburban Owner's Manual - Page 256

6. Connect the red positive (+) cable to the positive (+) terminal of the vehicle with the dead battery. 8. Now connect the black negative (-) cable to the good battery's negative (-) cable. Don't let the other end touch anything until the next step. The other end of the negative (-) cable doesn't go to the dead battery. It goes to a heavy unpainted metal part of the vehicle with the dead battery. 5-6