Hey guys I'm JD and I've got a 2008 Chevy Silverado extra cab 4 by 4 flex fuel truck with a 5.3 l vortec I have added a second alternator and second battery!! Separated the way this thing works the alternator for the truck side is a 2 PiN GM standard alternator and the second alternator is a 250 amp alternator that is charging a second battery!! So my question is with one battery of my alternator running the truck and the other alternator and battery running a audio system why are my headlights still dimming when the bass hits what is connecting the factory alternator and battery when there's no connection in the hot wire from the second alternator linking to the first alternator or to the first alternators battery?? The only connection made to the truck on the second alternator that is a 4-pin alternator that uses a mountable voltage regulator that you add to the firewall and it runs off of a 10 amp 5 amp fuse in the fuse box under the hood and you take out a 10 amp fuse anywhere in the big fuse box under the hood and replace it with the 10 5 amp connection just to get the voltage regulator to work?? Why would my lights be dimming when the bass hits whenever the charging wire off of the second alternator goes straight to the second battery and straight to the back of the truck to run amplifiers and does not connect into the truck system at all other than the 10 and 5 amp combined fuse to make the voltage regulator turn on and off??? Am I missing something in the internals of the truck that automatically connects these outlets to a wire that I have no clue where it would be because it's not hooked to nothing that I know of??? Please help I am stumped by this one???