My ignition issue has been both the "start" and "on" position.

When I first got the car, I was driving it home and it shut off on the freeway. I turned the key over and over for about 30 minutes. The car randomly started out of the blue and ran fine. I drove for about 10 minutes and then "click" it went off again. Again after fiddling around it suddenly came on and worked fine. (When it was off, I got no electrical lights or warnings when the key was turned.). It cut out again and did this until I got the ignition switch rebuilt. When it was rebuilt I was told the contacts were very loose inside and the interior components had carbon on them. The switch was rebuilt and worked fine. The car underwent a serious sorting and about 6 months later I tried to start it. I tuned the key to "start" and it turned over a couple times and then it would not crank when turned to the "start" position. I went through the whole electrical system thinking it could not be the ignition switch, but that was what it turned out to be.

If when the car shuts off, you do not have warning lights or seatbelt alarm it is probably the switch. My fuel pump would come on, but the dash lights and bells would not. If the dash lights come on and you have power in most systems it is probably down stream (relays or the ignition control box.)

I hope this helps. Let me know if you have more questions. We have similar but not the same model of car, so your system could be a little different.