limeyb,

This is very simple to check out. Put a DC voltmeter across the battery. It should read around 12 volts with engine off, then should go up to 13.5 to 14.5 volts once you start the engine and rev it up. If it stays at 12 volts, the alternator is not charging, but don't jump to conclusions and assume that the VR is the problem. It is very likely, but it takes five minutes to pull it and examine it.

Good luck,