Replacing/Rekeying Door Lock

How old is this? Could be worn tumblers...or, your key may be worn (doubtful though if it works in ignition)...you could also spray some graphite in there to lubricate them.

It's easy to replace the tumblers in a door lock and the dealer should sell them. I had to do this on my ZJ when somebody thought it would be funny to round out mine...you take off the door panel to get to the lock assembly, pull off that cylinder and note the tumblers and how they are arranged and just replace them the same.

Before doing that, spray some lube (graphite not WD40, etc.) in there...

But then again, you say it doesn't turn at all...hmmm. don't these have two different keys? Wonder if one works in the door and the other doesn't (will have to try it, as I always use the keyless)...It's possible the ignition is re-keyed...you can still replace the tumblers to match the ignition, but my advice would be to remove the key cylinder assembly and take that and the key to a locksmith.

To reiterate, the only thing you want to use in the locks is graphite...and the tumblers are generally brass, so no worries about rusting, but they can corrode.

However, it sounds like this may be the wrong key then, so if you can get the cylinder out, take it to a locksmith, or if you could get your ignition cylinder out, you could compare the tumblers and match them, but that would be a PITA (worth just paying LS)!

There should be a clip holding the cylinder onto the door and may be facing up (not easy to see)...You have an inspection mirror to get in there? Unless they changed the design though and perhaps it uses a large nut instead, but either way should be able to remove it. Maybe somebody has a FSM they could share that page...