my 1996 Cherokee sport sat all summer with a dead battery so thing fall I put a new battery in and it starts and runs fine but the headlights, the signal lights, and the brake lights don't work, at least not at first...after running for several minutes everything started working again, so I thought strange but ok...so then the jeep sat for just over a week and the same thing, started and ran fine but not lights until after it idled for several minutes then all magically worked again...very strange at least to me...any thoughts out there?...

Bill

 

May be corroded grounds in the engine bay. I suggest you disassemble each ground point and clean the wire ring terminals, then reassemble securely.

Make sure that battery connectors are clean as well.

 

Check this out.
https://www.cherokeeforum.com/f2/98-...gauges-133543/
scroll down to CCKEN #14 there are photos to show the ground pints to check and clean.