2003 Intrepid overhead light problem

I have a 2003 Intrepid and the overhead lights will flicker at the stranges times. Also when I went over a train track the car just stalled.

It started right backup but I believe that it has something to do with the overheard lights flickering. I have it at the dearlership now but they can't find anything. Help...

I have the same problem in my '98.......would love to know what is going on.

I have a "99" Intrepid and all my light(in and out)surge. I replaced the headlight swicth, the battery is new and the alternator is charging fine. I've also checked all connections and are clean and tight. It doesn't do it in town(that I can see). It will start doing it after I'm on the highway(after about 5 min.).
Once I slow down it won't do it no more.