Check battery condition....then do a test of the alternator for proper voltage and voltage recovery after a demand such as AC, window switch ect. If that all checks out then you need to do a voltage drop test on the motor side to see if the engine is grabbing a good solid ground. If all is good there the next check would be the k40 relay pack that houses the fuel pump relay and engine mgmt relay. All these items would contribute to wacky electrical issues with this car and cost almost nothing to fix. If you ruled theses issues out check the ground points on the car. If there is a bad ground electricity will find another path and can trigger some oddball conditions