Article: Although the negative terminal is not connected, still be careful to ensure the wrench used does not contact any other metal. If the cover is missing, then you should cover the post with a clean towel or a rag. Hand-tighten the nut until you can no longer turn it.

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Place the positive terminal back onto the positive post. Hand-tighten the nut until you can no longer turn it. Place a socket wrench over the nut and tighten the nut until it no longer turns. Place the cover over the positive post. Place the negative terminal back onto the negative post. Place a socket wrench over the nut and turn it until the nut is completely tightened. Remove all tools, towels or rags from the engine area. Lower the support bar and close the hood. Discard any rags or towels that came into contact with battery acid.