Mission complete!
I finally wrapped up the install of my second battery. Not surprisingly, there's really not much room in that engine compartment. I had to get slightly creative to mount the battery isolator and a circuit breaker. Thankfully, those fine Toyota engineers decided to give me a few empty, threaded holes in the engine side of the wheel well. But, first things first...
The first step was to install the monitor unit. I pondered installing the unit on underside of the dash or on the console; however, my end goal is to install VHF/UHF radio, I wanted to leave myself some freespace for the head unit, speaker, and mic. So, I decided to install the unit at the base of the seat belt pillar. I removed all the trim pieces and then drilled four small screw holes and one large 3/4 inch hole for the cable plug. I attached the mounting bracket, passed the cable through the hole, and then snapped the monitor unit onto the mounting bracket. Too easy. I then ran the wiring harness along with all the other wiring harnesses under the door sill and up through the firewall.
On the other side of the firewall, I had to figure out a place to install the isolator relay and a high capacity circuit breaker. Space was pretty limited along the firewall or fenders...and I had to deal with 4ga battery cable. To fix my problem, I built two aluminum L-brackets and drilled holes to mount each component and to bolt them to the existing, threaded holes (thanks again Toyota engineers). From there, it's just a matter of running cables. The IBS instructions are really good and make the job simple. I spent more time just trying to make it look decent and to keep the positive leads away from anything metalic and shiny.
The batteries are connected directly with a black, negative cable. I ran a red cable from the starter battery to the circuit breaker, then to the relay terminal. From there, it's run along the top of the firewall with the negative lead (in black heat shrink) to the other side of the engine compartment. Then, it's just a matter of connecting the terminal clamps and hooking up the batteries.
The end result is a 200 series that still starts (phew!) and a battery monitor that lights up to show the charge level and connection status. This is probably one of the easiest installs I've ever done on a vehicle. If it weren't for fabricating the brackets and figuring out how to mount everything, this would've taken a few hours to complete.
And now, on to installing the radio and some auxiliary plugs in the back of my LC.