Lights dim/radio dies

If you fix the VR and you still have problems, attack them again. Check the fuse panel busses (there are two, one "hot" and the other fed from "accessory" and if THEY show a difference to the battery, then trace that path back. ANYTHING you check MUST be loaded. EXAMPLE. If you are looking for drop in the accessory section of the fuse panel, turn on "stuff" like the heater, radio, whatever you can 'get' to come on to load the system.