There doesn't seem to be any instructions on the web on how to do this with a 3rd Gen 4Runner so I took it upon myself to write one up, so here ya go.

This modification will allow you to use your e-lock (electronic locking) differential in 2WD, 4HI and 4LO.
Begin by removing the 4 screws holding down the door sill.



Then remove the kick panel by pulling it straight back.



Now locate your 4WD control system, it's a black box that says Toyota in big letters on it with a white harness plugged into the bottom of it.



Disconnet the harness and locate 2 wires. One is be Blue w/ Red stripe, and the other is Green w/ Orange stripe. The Blue/Red wire controlls only being able to use the locking diff in 4Lo. The the Green/Orange wire controll the 5mph safety.



Next, cut the Blue/Red and Green/Orange wires and twist them together. Using another piece of wire, connect one end to your twisted wires and connect the other end to a ground. You can also ground them individually if you only want to disable one of them.




Once everything is connected, tape off the two remaining wire that are no longer used and plug your harness back into the 4WD control box



The advantage to locking your differential is so that both tires will spin together instead of individually and thus giving you better traction. HOWEVER, I do not suggest leaving this on for long periods of time on dry pavement while in 2WD because it can wear your tires unevenly and also may cause problems with your differential. But however you decide to use it, enjoy it.

id suggest leaving the 5mph safety alone this is so it wont engage the locker with speeds above 5mph but the locker will still work over 5mph when its locked

Really, everything I read said that it disengages the locker if you exceed,...some said 5mph, some said 15mph. If that is the case I want to leave it like that. Driving through Colorado mountain highways can some times require having to change into 4wd while still at high speed and I want to be able to do that with the locker.

I found by doing this it fooled the computer into thinking it was in 4low and the overdrive doesn't work , and the shift patterns aren't the same. I put my ground on a switch and labelled it . (used one of the spaces on the left side of dash)

My "grey wire" mod was done went I bought it. I checked it out for comparison. The blue wire is the only one cut, and the side connected to the plug is tapped and grounded. I have gone up to 30 or so m/h in 2H and 4H. You do not want to take turns with it engage, as it will tear up your tires and mess up your steering, off road excepted of course...

I like this mod for offroading because it gives me the freedom to use 4H, 4L and the locker in any combination.

Matt, I officially declare this the "blue wire" mod. These are 4Runners were talking about, so why scab off the taco's!! ha

Here is the photo of mine.

I agree, I should have named this thread the blue wire mod lol

i did my mod with a buddie, and it doesnt affect my shifting, or anything like that and it works at any speed except to be engaged you have to slow to below 5mph, but after its engaged you can go fast again.

Is this for only locking rear diffs or could it be used for 01-02 center diff locking too

Thanks Matt and everyone else! I just did this mod, it took me about 10-15 minutes and it works great. Thanks again.

well im glad to see i helped everyone

Sorry I didnt see you're post I must have skimmed over it. No this does not work for 01's and 02's cause they have vcs insteed. What your center lock does is distribute power to the front and rear 50/50. So there is no actually locking of anything involved.

so have we definitively decided it's the blue wire? not the other two mentioned in the op?

applies to a '99

as far as i know they should all be a blue wire with a red stripe

ok no go on the orange wire it's just the blue one?!
the write up above is good but it gets confusing as the thread goes on as it sounds like matt whatever did something wrong, lol

why did home dude get banhammered?....can i ask that ? lol