XJDC

Okay, this may or may not be a common problem but if your Cherokee starter cranks with the key off or even with the key out, this may be your thread.

First off the issue with mine. I would start the truck and it would fire up, but the starter would continue to crank intermittently with the engine running. To shut it off I pulled the starter relay, then plugged it back in, or start the truck and put it in gear which pulled ground to the relay through the NSS. So I unplugged my aftermarket remote start. It did it a couple more times and stopped for a while. Thought I solved it. Then, last Saturday, when I was no where near my Jeep, it cranked and cranked till the battery died and fried my starter (which smells terrible). So onto the cause. Water leak - from the antennae grommet where it passes through the fender into the body behind the passenger kick panel FUSE BLOCK.

This was causing a short to power on the yellow/red wire to the starter relay in the under hood fuse block. I had anywhere from .78 volts to 12.2 or B+ voltage. Bought a used fuse block, cleaned all the connectors, now I have 0 volts at the yellow/red wire to the starter relay, as I should.

So TL; DR If you have weird electrical gremlins, open up your kick panel fuse block before you fry something else.