Not really, I have a CB, dual band radio, and very minor stereo upgrade.
Here's what my thinking was...
With the added current available from the aftermarket alternator, it's recommended to up the AWG of that singular OEM wire to the driver side battery anyway.
Others have not and been ok (I had spent a lot of time reading reviews and comments regarding the aftermarket hot rodded alternators)
There is a 140amp fuse in the fuse block for the alternator, than the path continues on to the driver's side battery, than to the wire across the radiator to the passenger side battery.
They sell a kit to replace the initial path from the alternator to the drivers side battery (fuse and wire and lugs), but the lug was huge and wouldn't fit well on the 99 alternator with the insulator in place.. no way I was loosing or reducing that insulator.
My OEM harnesses are in great shape, and I hate butchering such items, but I have to be secure in the fact I won't blow the 140amp fuse (my engineering OCD).
So after looking at the wiring, I came to the conclusion:
The + path to the two batteries is not symmetrical, not even close, and the passenger side battery has a very long lead between the drivers side and it - never mind the long path from the Alternator thru the fuse and finally to the driver side battery.
By adding that one "wire and fuse" from the alternator to the passenger side battery I can get more copper in there, with less intrusive work, and make the system 'more' symmetrical
It was easy, only special tools were the hydraulic lug crimper and dremel. I had the dremel, and wanted a bigger lug crimper anyway.
http://www.harborfreight.com/hydraulic-wire-crimping-tool-66150.html
Just pick thru what's on the shelf and makes sure it's not leaking from the get go (got that hint from reading reviews on line about the crimper... others have returned a few, and realized many were leaking on the shelf from the start and were the bad ones (not just messy from the factory), and the ones not leaking on the shelf seemed to be G2G.)
I crimped ferrels (barrels) on the wire ends, where the wire ends go into the fuse holder and the fuse holder had a couple of set screws to secure the "wire ends".
I never liked putting extreme multistrand wire under one or two set screws.
If I had a solder pot I would have dipped after crimp, but don't , so settled on the a good tight ferrel and than crimped.
Found a nice fuse holder on Amazon, seems to be sealed well, there are many to choose from on there.
I secured the fuse holder to the battery bracket hold down rod.