Where does the other end of negative battery cable go on a 1991 jeep wrangler go?

On a 1991 Jeep Wrangler, the negative (-) battery cable's other end should connect to a significant ground point on the vehicle's chassis. This is usually a bolt or threaded stud on the engine block or a bolt on the body near the battery. The location is designed to provide a solid, low-resistance connection to ground the entire electrical system.

It's not typically connected to the frame itself directly, but rather to a specifically designed grounding point that's attached to the frame. Look for a substantial bolt, often painted black, that's easily accessible and shows signs of being used as a ground.

If you're unsure, consult a wiring diagram specific to your 1991 Jeep Wrangler. A repair manual (Haynes or Chilton are good options) would be very helpful in locating this ground point accurately. You can also often find diagrams online, but verify the accuracy by cross-referencing several sources.