Hi all,

sometimes I have trouble starting as follows:
Either
doesn't crank
or
cranks but no spark.
Are there any usual suspects in the wiring? I got the knee blocker off, there are a bunch of unused wiretaps (in the red, orange and blue fat wires for example - is that a stock feature?), but no obvious issues. Somebody has been in the yellow wire before, but it's cleanly put together again. Stunning that it randomly behaves differently. Half the time it fires up just fine.

Battery, fuel filter, spark plugs, plug wires, rotor and cap are brand new. It's a 96 Cherokee. Thanks!

 

I would start by checking Neutral Safety Switch and Crank Sensor, sounds like the symptoms of both going bad or having bad connections.
I've got the connectors in my parts jeep, I'm betting yours used to have a remote starter or good alarm system.