rat - you don't have any "factory electronics", and a modern radio probably takes less power than an original would - the reason the lights fade at idle is the generator isn't putting out enough or the regulator is maladjusted, that's not the original behavior, there's no reason a good original generator won't handle anything you want to put on the truck - you likely have a worn out generator, either take it to an auto electric shop and have it evaluated [best to have the regulator with it] and get it rebuilt or get a higher output one or go with an alternator, nothing to cause concern
Bill
