Hi, I have a 98 Jimmy. Last week as I was driving down the road, my dash lights and my speedometer went crazy for a second and I figured I was in trouble. It went back to normal and that was it. A few days later, it did the same thing, but stalled. I had to pull over and it started about 20 minutes later. Yesterday it stalled twice on the way to work while going about 50 MPH. I shifted to neutral both times as I was rolling and got it started and kept going. This morning I went to start it and it wouldn't start. I was just about to swich vehicles and tried it one more time and it started right up.
I have noticed that when it is doing this, the gas gauge and the voltage gauge are not moving. The battery is 2 1/2 years old, and registers fine on a battery tester. Anyone have any other ideas?

Also, when it does this, it will not shift out of park

It was the ignition switch. Had it done for just under $200.