[scottyb]

The 7 batteries cable up the same as 6 batteries do. No mystery here.
Connect (+) to (-) from one end of the pack to the other. Use your meter to verify you have 42v (or more) between the main (+) and main (-) to insure you have done this correctly.

The small gauge wires supply 12v to accessories. Headlights may be 12v or 36v so a few cell phone pics before you started would be priceless now.
Lets assume everything is 12v (safe starting place). You should use a 48 to 12v reducer but that's another topic of discussion. Assuming you do not have one because Western didn't install them for cost reasons ...

Use your meter to find 12v on your battery pack. Place the red test lead on main (+) and go 2 batteries away to (-) you should read 12-13v.
Note you can find 12v by testing across any 2 batteries in the pack.

Assume the small red wires with fuse are (+) and put them on the main (+) terminal and hold one of the black wires to the (-) terminal where you read 12v with your meter. Have an assistant test the lights or trunk latch or fan... repeat the process for the other black wires. Connect the black wires that make 12v stuff work at this terminal.

I hope this helps