dual alternator setup

It is best to take it to a mechanic, Most will run one output to your car (regular) and run the other for you system( to another battery in the trunk)

no do not wire them togather, if your using 2 alternators, use one for system only and the other for your car...I have the dual alternators in my 1992 ford mustand, and i fried alot of sh*t not knowing what i was doing, i hooked the 2 togather wich over charged the system and well ended up having to replace alot of things, than a helping stranger off this here site told me what i did wrong, wich is what i kinda figured went wrong, but told me i could still run the 2 alternators but one for my system alone, so that is what i did, i have no bat. or any thing comming off of the alt.....only thing comming off my second alt. is my 2 ga amp wire straight to the amp and works great......

Thanx for the replies. The reason I was going to add a second (stock) alternator, was because my High Output alternator does not perform well at idle (in gear). I usually get around 12.6 volts under these conditions. To top it off, the alternator already comes with an overdrive pulley. Until I install the second alternator, I will simply up the idle by about 150 rpm's ..

If you were to diode isolate them, you can run all of the alternators you want to one battery, and they would not act as sink to the other, but both would always source. Each, of course would require it's own regulator, with a sense lead to the INPUT SIDE of the isolator, and a trigger lead to get them both to start generating. Since the field on most alternators today is self-exciting, if you diode isolate them, they would not see each other, but they would also not see the battery, so they would simply free-wheel forever, because there is no voltage to set-up the excitation field, and the battery would never charge. It can be done, but I think it would be a bit too much work, to make it worth your while.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."