p38 flickering dash lights

hi all , ive seen a post on here some place about this but buggered if i can find it .
i fitted a replacement engine in my 1997 4.6 hse complete with all ancillaries and the only fault now is the dash lights and headlights tend to flicker whilst the engine is running , it didnt do it before and its only slight , any idea`s anyone , going to check it this morning with the multimeter , but in the meantime i would appreciate any veiws on what the problem may be cheers .
rick.

Hi Rick,
I posted an item on the forum last year regarding "Pulsing" of the electrics on my P38, 4.6. The pulsing was at a steady pace and because I was concerned about cooking one or more of the ECU's due to the voltage surge (Up to 18V) I changed the alternator and the problem disappeared. I have since had my old alternator checked over and as a result, the voltage reulator was replaced and the voltage reading is rock steady-I am keeping it as a spare. Cost of fitting the regulator over here was €40 (£26)