went to work jeep was running fine .. went to go home jeep would not start... no clicking sounds, nothing. replaced ignition switch and all relays that could be found. can jump out the starter and it will turn over but not fire. headlights and interior light work but nothing else. as you point out it is probable the fusable link? next question is where the #$#@ are the fusable links located this must be the week for 1990 yj"s

Fusible links performn the same function as a fuse - protecting the wiring and stuff that's downstream from them - so you'll find them as close electrically to the battery as possible. Usually that means that one end is at the starter solenoid and the other is crimped or soldered to the big wire that runs around the firewall to the main connector on the engine compartment side of the fuse box.

They look like just another piece of wire, about four inches long. Best way to test them is just to pull on the wire. If the link has burned out the insulation jacket can still be good but it will stretch. If the link is good it won't stretch.

the fusible links for the starting/ignition system come off the starter relay...it's bolted to the firewall just below and inboard of the battery...on mine, the links looked like a big, fat (3/8" across, 1 inch long) black rubber thing around the wire...grab the green bit below that which goes to the starter relay...good wire has a particular feel to it - kind of stiff, a bit of girth...if the wires feel soft and really flexy (like there's nothing but insulation) they're probably shot...

now, the important part...figure out why it's shot! it could just be old and worn out - we ARE looking at 15 year old vehicles here...in my case, there was a short under the dash...when we plugged stuff back in (without repairing the short, we saw smoke pouring quite angrily out from the wiring harness both under the hood and under the dash...

after repairing the fusible links, take the plugs out of the ignition switch, and check for continuity between the wires and a good ground (bolts on the firewall, bare metal under the dash, etc...in particular, check the 10ga red wire, and the double yellow wire (2 wires which go into 1 connector)...my yellows were shorted out...i know that because they are the most damaged/melted, indicating they had the most power...you don't want to have any continuity between these and ground...