Ignition Switch?

I think my problem is the ignition switch (down in the column), but want to get some confirmation before I buy the part and begin the install.

Vehicle data: '89 Jeep Wagoneer Limited (XJ), 4.0L, AW4, NP242. No engine mods except cold air intake. Other mods shouldn't impact this issue (lift, SYE, 8.8 rear, lockers, etc.)

Symptoms: Will start and run only for a moment, then dies. Will keep running if I hold the key in the start position, but dies immediately after I release the key to the run position. Test light confirms that power to the fuel pump dies immediately upon release of key from start to run.

Was out wheelin' and "hot wired" power to the fuel pump from the tail light wire. As long as my parking lights were on, Jeep ran fine. Turn lights off and it dies. It's kind of a unique kill switch and could probably fool a wannabe thief, but I'd like to make the proper repair!

So, do the experts here think the ignition switch is the culprit?

Thanks in advance for your input and assistance!

Jump the ballast resistor, inside fender well drivers side. Replace the reisitor or just leave it jumped, your choice.

Yup. Forgot to mention that the ballast resistor is already jumped!

Since the ballast resistor is already bypassed, then I would suspect the ignition switch. I simplified the situation and bypassed the ign switch and I use a toggle switch and a push button for the starter.

The yellow wire circuit from the ignition switch, powers up a bunch of stuff, including power in to the fuel pump relay actuator coil (86 pin on the fuel pump relay). The ground for the fuel pump relay actuator coil (85 pin) is through the ECU. The red wire, 30 pin on the relay, comes from a fusible link and is constant power and the 87 pin is power to the pump orange wire (sometimes orange with a black stripe, sometimes just orange).

The orange wire (usually marked "BAL") from the starter relay bypasses the relay and the ballast resistor during a start. Also a good spot to get emergency power to the fuel pump, bypassing the other stuff.

The ignition switch for this particular set of circumstances isn't likely, as the same circuit (yellow wire) would shut down your ignition module..

Most likely is a bad fusible link, maybe a fuel pump relay issue/female contacts for the relay or an open wire someplace in the engine bay.

OK. Thanks for the detailed input! I'll start chasing the problem further before I tackle the ignition switch. I should have a chance to work on it later today/tonight. I'll report what I find.

Just thought I'd follow up. Since the issue was gone after I got home from the trail (with my tail light power trick), I surmised it was the ignition switch and replaced it. The switch must have been the problem as it's all good now and has survived two more trail runs without a hitch!