I've jumped the lamps and both work.
I've replaced the mfs.
I've replaced the headlight switch.
The fuse in the pdc has power on both sides.
The sockets are clean and di greased.
No power to the low beam fuses.
Where do the low beam fuses get their power?
My manual looks like they get it from the mfs.
1998 4.0

 

if they have not changed much on jeeps, everything but the ground is through the switch. that's why they tend to fail at a way higher rate then other manufacturer's do.

you can get a kit that puts relays in the engine bay and the switch just turns on the relays and gives you an unbelievable difference in lighting power.

i imagine you also checked the grounds but since the highs work, its probably the switch

 

I just replaced the switch.

 

and it fixed it?

 

Hey Pocahontas I would say you need to figure out which pin on the MFS controls the lights, then follow the associated wire on that pin from the MFS as best you can until you hopefully find the issue. If it is one pin & wire that controls both hi & lo beams, I guess it doesn't matter if you follow the wire to find an issue because as you said, the hi beams work. If there are 2 pins on the MFS that controls lights... one for hi and one for lo, then that could really help you find the problem on the lo beam pin and associated wires. Hope that makes sense....

 

This for a 95, but possibly the same as your 98.

https://www.cherokeeforum.com/f2/95-...lights-207614/

 

The fuses are powered by the beam selector switch. If you try flashing your headlights over and over you may get something to work which would point towards the switch being bad. Another component that gets full current during operation. It could even be the connector to it has melted.