Q: I have a question about jump-starting a dead battery. One expert told me not to connect the negative cable to terminal on the dead battery but rather to connect it to a grounding point. Yet, when our 2016 Subaru Impreza had a dead battery, the mechanic did connect the negative cable to the negative terminal on the dead battery. The car started fine, and we've had no more battery problems since then.
Why not connect to the negative terminal on the dead battery? Are both ways OK? What problems might occur?