hey i have a 93 Sedan Deville and lately it has had an intermintent problem. i could be driving down the highway or stopping at a stop sign and for no apparent reason the electric will glitch. when it glitches the aftermarket radio restarts, the headlights flicker, i loose all my instraments (digital dash), sometimes it will make the engine stumble or every now and again it will kill the engine. but if i turn the key off and try to restart it, it fires right up. sometimes when the power glitches it will mess up the speedo. the other day i had the cruise set at 72 when it did it, and suddenly im doing "85". but again if i shut it off and restart it, everything is fine. i've had the car since nov. of '04 and when i bought it i put in a car audio system and an after market car alarm. never had any problems till a couple of months ago. any one got any ideas???

 

Check connections at battery, poor grounds both sides of core support and at block near starter, and check for codes and post them E and F.