92 Jeep won't start suddenly

OK jeep worked fine a week ago now when I got into it and turned it does not start. Now I'm thinking 3 things might cause it, malfunctioning alarm, bad msd ignition box, or crank sensor. THe alarm seems to be functioning normally, except the drivers door does not disable it anymore(this started 3 weeks ago, and why I think it might be the alarm). I pulled the wire off the coil and with a plug in it grounded I didn't see any spark at all so I know it's electrical. Anyone have good ideas for quick troubleshooting?
Is there a quick way to disable the alarm completely on a 92?
Would the crank sensor stop all spark, or would it just be mistimed if its going bad? I thought the computer would kick in a default setting to keep it running. Thanks for any and all help. It's been a long time since I've been on the forum, I actually remember when we moved the forum and it became the naxja....wow I can't believe I've had my jeep that long!

what happens when you put the key in? try putting it in neutral or wiggling the shifter.

ha ha...I already know that trick well...been putting off the neutral starter switch rebuild for a couple years. But I think I found my problem, after reading more posts...specifically the cps, I decided to go take a look at it and try the re-plug thing...but to my amazement it appears that the wire going to the cps has all of a sudden decided to fall off! Now how does a wire like this suddenly decide to just break away from the sensor? Theres no moving parts around there...and to suddenly do it while it's been parked for a week!! So sometime between the last time i drove it and a week later the cps lead wire "fell" off. I know my jeep is old, but it's not that old that wires should break apart...maybe a squirrel chewed it off...hell a squirrel couldn't even get into that tight space. Hopefully I'll have time to change it tomorrow.

Now how does a wire like this suddenly decide to just break away from the sensor?

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Heat. Over time heat from the exhaust wears down the leads to the CPS until one day :wierd: squirrels. This happens if the wiring is not routed away from the heat source. Hope this fixes your problem.

DAMN THOSE SQIRRELS! ha. Boy I hope that doesn't mean wires are just going to suddenly start breaking in half all over the place....I've started getting a bunch of electrical things going wrong in the last few weeks. Key won't disable alarm from drivers door(have to unlock passenger first to get in), right rear window doesn't work, won't start now, I'm worried about what's next....

If the crank sensor is shorted your jeep won't start. My crank sensor went out on my 98 XJ on the top of a mountain a month ago and I had to get towed 75 miles back home (the first seven miles there was no road just a 3+ rock garden).

The first think I noticed was all the gauges were out (the lights worked but the volt/gas/temp/etc guages were all sitting on zero). The problem I found out $1000 later was that when one of five sensors go it kills the +5 volt supply coming from the PCM. With the 5v supply gone there are no codes and a reader can't connect. I purchased a rebuilt PCM before I found out the real problem.

The Chrysler Service manual test procedure said the PCM was bad but when you run the test procedure in the PCM manual (which I didn't have at the time) it helps you single out the problem right away.