Stereo & Electronics - Air bag light and high voltage

The car is a 94 formula. Just finished swapping the motor and the car will start up run fine then the voltage gauge goes crazy high and the air bag light will start flashing. I'm Thinking it might be a ground just don't know which one... or if it might be the alternator. Thanks

No ideas... well I took the alternator down to a local shop that said everything was fine with the alternator. BTW the alternator is a power master 200 amp if that gives anyone any ideas.