revving by its self again!!!!!!!

[uzz31GTIan]

Im having the same problem again with my V8 soarer the thing keeps reving up and down by its self. This happend to me a while ago it was simple to fix as the dash was flashing "battery not charging" so a changed the alternator and the problem went. Now its back and this time there are no warning lights on dash, alternator has been checked and is fine no leaking from power steering pump either. Please help if you can

Cheers
Ian