There are 2 fuses. One in the TCM harness under the dash and the other in the fuse box. It won't stop it from manually shifting though. The fuse holder on the TCM harness in mine was corroded and broken where you couldn't see it. There should be power at that fuse with the motor running. I used a jumper wire before I found the broken fuse holder.
'84 XJ should be external slave. The ones I've had pre '87 have all been external. I even converted an internal slave bell to external with the parts from another one and I drilled the bell for the pivot ball I got from the "HELP!" rack.
The module under the coil is good? Mine quit up in Canada. Fortunately at my son's place so I was able to score the coilpack and ignition module off his and I got back on the road again. There is a repair wiring harness for the CPS that goes directly to the computer as well. Last time I bought a dealer CPS it came with it (in '99). Mine turned out to be a short somewhere that overheated the fuel injection box, but after it cooled it ran another 20 minutes again. Turned out the PO grounded the heater fan to the ECM and aimed the defrost hose directly at it too.
Silly question, but you checked the fuse for the gauges, right? The cruise won't work on '91 without the speedo working because it reads off the back of the gauges that year. '92ish up they added a pin on the trans adapter to run it direct.
When it rains, it pours, right? I need to change my trans too and I've been too sick to do it. Mine is cruising around with 1/2 ATF and 1/2 antifreeze.
I had my ex-wife get mad and shove the shifter into reverse, but it skidded then locked into park and the motor/trans rotated under the hood several times before punching the hood and floor.
I put a 4.0L in place of the 4.2L in my '84 J10 along with an AW4. To get it so I can drive it to town from my cabin I built an adapter to bolt a spare MC2100 to the EFI intake. The injectors stay in place. I ran out of time last summer and the road had a landslide in Dec so it awaits a month or so that I can get up there. GM HEI dist with AMC gear on it and electric fuel pump. Later it will be LPG powered.