Super CHARGE!

Sometimes while my car is running (it doesn`t matter what rpm) the ammeter will just peg and all the lights ,etc., will get really bright. It may go on for 10- 15 secs., then return to normal only to do it again whenever.I have the Mopar regulator 3690732 with Mopar elec ign.w/chrome box and 1/4 ohm resistor as well as a 45amp alternator. What would cause the sudden surge of electricity through the system like this?