A Drop In Voltage ?
 

Please tell me if anyone has ever experience this nightmare.While driving at an average highway speed, i turn my headlights on and the car gave a sudden jerk and the radio cuts off for about 10 secounds, this happen so infrequently.My car is a 1997 boxster with only 26000 miles, i just had a new interstate battery install and the charging sytem checked at the dealership.Has anyone had a similar experience. thank you

your ignition switch is going bad. this is a common problem.

my service lady told me my ignition switch had been changed in 1998, because of a recall then. As i said this problem is so infrequent, always very sudden, you turn the head lights on or as simple as signaling to change lanes you get the sudden jerk or drop in power and the the radio if on, cuts off for a brief secound

Did it do this before you changed the battery?

Could be - battery, alternator, ignition switch.

yes it did before the battery got changed and the the alternator was fine.The car drives great, but as i said, out of a sudden when you turn the light switch on when in motion this problem occurs, it's really once in a while occurence

+1... classic symptom

Even if the ignition switch was changed due to a recall in the past, the 'new' switch has failed.

Look for replacement on ebay, easy diy and much cheaper there

thank you, i am taking the car to the dealership on monday, will see what they say. but i appreciate the input.I just hope it is the ignition switch.