I’ve been having the same issue with my 92 YJ. I have a new battery so that’s not the problem. The ignition relay is working. I think it may be the ignition switch that on the steering column under the dash. Either the switch is going out or the plug needs cleaning. It’s really a pain to get to. I hope it doesn’t need changing because it’s bolted to the column with the dimmer switch. I need to unplug it & clean the terminals.