1996 Mazda 626 Speedometer pegs, runs 15 seconds then stall

I just performed major repairs. New CV shafts and front brakes. Topped off low trans. Fluid. Drove home approx. 5 miles. Checked trans. Fluid. Still low, topped off. I left to drive to local car wash. With key to the ON position, the speedometer pegged out, odometer turned miles on its own, all this for a second. Started engine, drove vehicle thinking nothing but a momentary glitch. Went to car wash, washed the undercarriage. Went to start car, problem worsened, drove 1 mile, car died at traffic light. Had to have towed home. Disconnected battery and computer, left overnight. Reconnected next day. Problem not only remained, it worsened. At one point the O/D OFF light continued flashing. That was a first.
Now key ON, speedometer pegs, engine starts to cold idle for approx. 10 seconds, then stalls.