Well, I had that happen years ago and it was not the ignition switch. I still have that trouble but too lazy to fix it now. It is the wire to the starter, the small one. You most likely have to fix the connector that hooks to the wire.

When this problem happens now, I just have to reach under and get my hand a little greasy move the connection and it will start, no monkeying with the key at all.

Now on mine it is the connection at the starter, you may have to check that wire all the way back to where you can find a corroded or cut or something odd.

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