1998 Jeep Wrangler Sport cranks but will not start and dash gauges don't come on either when the key is turned on?

Without further diagnostics, I'm not sure how to answer. Having said that, an engine only needs three things to work: Air, gas and fire. If you're not seeing any lights, you have a potential electrical failure which may mean no fire. This is how to determine if this is true: 1. Disconnect one of your spark plug wires 2. Insert a long screwdriver into the plugwire end 3. Lay the screwdriver so that it rests 1/4 inch, or less, away from a metal part within the engine compartment (It CANNOT touch anything metal directly) 4 Have a freind turn the engine over while you watch the 1/4 gap between the screwdriver and the metal 5. It should arc a spark from the screw driver to the metal, indicateing you're getting fire to at the plugs. If you don't get a spark, that's your problem. You'll need to track down the source of the power short. Hope this is of some value.