hi team i have a 1999 jeep cherokee 4.0 liter inline 6. got this crazy problem were some morning i go out and crank up jeep.and none of the instrument on panel is working.(gas,coolant,RPM,battery) nothing working not even speed gauge.sometime it will be like that for half a day.then if i hit a bump in the road or cross a railroad track all of the instrument panel start working like new. it do this about every two week.
Those XJs were susceptible to corrosion at the instrument cluster connector. Remove the instument cluster, clean the contacts and apply dielectric grease.