I have a 1999 Jeep Cherokee Sport 4.0L with about 128,000 miles on it. It has not had many issues electrically or mechanically up until now. I came outside yesterday afternoon to run some erands and when I went to start the truck it would just crank and crank and not turn over. The battery had good voltage and the key turns on and the idiot lights on the dash cycle on and off but none of the gauges move. The truck just cranks and cranks and cranks. The oil pressure, fuel, water temp, and battery all stay below the lines and do not move. I tried hooking up a Mac scanner to the truck to see if there were any codes but the scanner keept telling me that the key needs to be on and will not check for codes/problems?? I spoke to a couple of people and they told me it might/could be a CPS sensor or an ignitioin switch? I do get the dash lights, mileage, radio, and most other ignition functions so I have no idea if this is ignition related or not. If anyone had any info or insight as to what this could be, that would be great. Thanks for any help in advance!!!