After searching for a while, I found this link The "Two-Low" mod - TTORA Forum and read through all four pages. It was pretty confusing and I figured it out. If you want low range rear wheel drive without doing a manual hub swap, here is what you do:

There are two sets of wires that go into the transfer case on the driver's side and on the passenger side. These have a blue plastic plug. On the passenger side, cut the yellow/black wire and put in a switch or a quick disconnect. This will trick the ADD system to think the transfer case is in 2-Hi when the circuit is broken. On my truck, the plug was cut out and the wires were twisted together. I soldered the blue one back into place.

To use 4WD, just re-connect the wire.



I hope this helps someone do this awesome mod!

Here's the switch I installed as a circuit interrupter for the yellow/black wire. I have used it many times and works great. The wire is routed through the transmission shifter hole.

write up: ADD 2wd LOW

Check out my write up about half way down that page. Very easy and useful mod!

I haven't tried it yet, but is it safe to flip the ADD on or off while the transfer case is in 4wd?