why does car electical system goes on and off affecting engine

What is your question?

int ermittent problem, i have had new alternator put on,throttle body replaced,battery replaced ,car seems to stutter,gagues on in and out engine shuts down will start back up,notice if ac or heat on will occur....cant figure out if problem is electrical or mechanical it also makes a whistling goes away when i accelerate.

What makes this problem better or worse?

nothing

How long has your 2002 Lincoln Town Car had this problem?

couple of years