Idle drops randomly

[Gross_00-0088]

Some times in will drop down to about 100-200 rpms then back up to around 600. I have noticed my volts drop around 12.4 volts some times then I hit my window switch then back up to 14.2 it goes. It just bugs the crap out of me. It only seems to do it durring the day. But at night when I have headlights on it never does. Never tried to drive it with during the day with the headlights on to see if it still does it. I have checked alternater and battery connections and changed them both out and still does it. Any clue anybody? Thanks in advance...

[RTW DC2R]

maybe a bad ground? or when was the last time you did some basic maintenance like changing plugs, cap, rotor? any CEL codes? any modifications to the motor or electronics?

[Gross_00-0088]

plugs,wires,rotor,cap and dizzy all changed out about 8000-9000 miles ago. I rebuilt the motor about 7000 miles ago started having the issue shortly after a built it. I have checked all my grounds the LOOK good, but I mights take them off and try replacing the wires.