Idunno

The key is not rotating to the start position. Before I realized that the ignition tumbler was not fully rotating to the start position I checked all other circuit devices (relay, battery, cabling, starter, etc.) The key will rotate to the position that closes the fuel pump circuit. I can here it momentarily pressurizing the rail, but it will not rotate past that position.

Is this a tumbler problem or is there another related issue preventing full tumbler rotation?

Thanks,

tech

There is a part that goes from the key to the ignition switch and that part can brake and cause the problem you have . to see if that is the problem you need to remove the ignition switch to see the broken part .

Idunno

Thanks, tech. I opened up the column to access the switch location. There's what appears to be a cable with a quick disconnect connector just beneath the tumbler. It routes forward, around to the right and back towards the tunnel beneath the center console. I removed and reinstalled it into the aluminum housing on the column using the quick disconnect with no change in the no-start problem. I also checked the ignition voltage normally at the solenoid when the key is moved to the start position. There's no voltage there and that tells me that I might be correct in the problem with the lack of full rotation of the cylinder. My 96 Cherokee key rotation confirms that as well.

Just for grins I tried the door key in the ignition and it operates the tumbler without any catching or binding, like the ignition key's smooth action, so I'm going to get the cylinder lock replaced. Thinking as I'm typing this, maybe there's a piece of debris from the tumbler that broke off internally and is preventing full rotation.

Idunno

Well, I replaced the ignition lock cylinder and it brought back to life the warning beeper for leaving the key in the ignition. But, that's it. I think I have another gremlin to defeat. Still no start. Looking at the diagrams for the starting circuit, the only problem I have is a lack of power through to the starter solenoid.

Idunno

All electrical wiring and voltages check out. I opened the distribution box just for grins and everything there was in good condition. Thinking backwards to the ignition switch, I opened the column and removed the ignition switch and pin. When I separated the pin from the switch a piece of metal fell out. It was the end of the pin that's normally inserted in the rotary switch and rotated by the key cylinder lock. That was the problem all along. I should have gone with my first instinct to dismantle the switch when I was sure it wasn't fully rotating.

https://app.box.com/s/3z7qdw40jnc01bqd356vh30te4de3f9i