My 93 stopped working and it was the sender on the tcase
93 YJ 3.5 lift 31x10.50 Dunlops on soft 8s 8K winch Tj Ft bumper RRC rear bumper w/tire mt RRC rock rails TJ flares'dual Optima red topsw/homemade relay/jumpstart mode Congo cage and Garman Wilderness rack. CB and Fireband 2-ways undercover LED red lites and siren. Full EMS gear including 02 and AED A work in progress never finished!!!!
Your speedometer is going to be mechanical I think. If not it still works the same way you just have a VSS(vehicle speed sensor) to deal with also. The cable runs from the back of the speedometer to the tail housing of the T-case.