97 Ford Taurus dying problem

I have a problem in regarding a electrical issue. My 97 taurus with 3.0 ohv shuts down randomly sometimes when it shuts down it restarts it self and throws me towards traffic. It getting a little dangerous. I believe this is a electrical because all the the dash light will cut sometimes when it does. Usually before it dies shuts down the lights will dim and the radio will turn off and on where should I start looking?