Could be the ignition switch, but I'd check some other things first. For starters, clean your battery terminals. Dirty ones will conduct intermittently and cause all kinds of weirdness. After that, make sure your grounds are good. A '94 model is getting to the age when ground problems start getting common. If all that checks out, then I would get out the wiring diagrams and start tracing the current path to/from the ignition switch in order to identify the problem.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.