E Locker Wiring Installation

New to the forum here and just bought a 97 Tacoma 3.4L xtracab 4x4. A previous owner swapped in an e locker rear diff with the OEM harness, the ECU, and the dash switch, but the wiring was never done. I am hoping to complete this project and get the e locker usable!

I've found many threads on this but please don't tell me to search before posting. I'm simply trying to get help correlating what I've found online to what is actually present in my vehicle.

The elocker is off of a 1st generation 4runner, but with the part number on the ECU, they said they couldn't clarify which year it came from. There's a tag attached to the ECU that says "2000-4R-372C" so I'm guessing it's a 2000 (not sure what the 372C is about).

I'm hoping that you all can help give me some guidance on wiring this up. I know there's all sorts of threads about this swap that have been very helpful, but this is more for my own clarification since I have never really done any of my own wiring except the audio side of things.

- Are all the wire colors the same across 1st gen and between the Tacoma and 4Runner?
- What is the benefit of using the OEM install/ECU vs something like the harness from low range?
- The cluster has the "DIFF LOCK" light, but I'm unsure how to wire it to work.

I'm hoping to get some advice on what wires need to go where from the ECU, the switch, and into the harnesses under the dash to make everything function as intended. I'll be documenting what I do in case someone else can find this useful in the future.

Thanks so much for any help you can provide!


The elocker with oem harness:

The ECU and switch (the one that doesn't say 372C on it is the truck's original part and has 4 wires coming off the harness):

The existing wire harnesses in the vehicle. Not sure if any of these can be used?
Backside of the one at the top of the image:
Bottom one:

Two more harnesses up under the dash:

 

@mechanicjon

 

I bought a wire harness from 12voltguy, worked out great. Vary simple and has it's own light and a guarded switch like an aircraft has...I think it's pretty cool and much easier than swapping ecu n what not

 

Easy installation.
That white plug near the ign switch is not the correct one. If your truck has it, it will be on the left side of column near dimmer knob.

 

Doesn't sound like "easy installation" to me. I had mine don't in about 30 min with the harness from 12voltguy

 

Been looking through the wiring diagrams, but I'm struggling to conceptualize which wires are coming from where in the existing wire harness and also what they would connect to in the system I'm trying to install. Like, I see that there would be a "grey" wire coming from the 4wd ECU, but there isn't one on the ecu.
What is the ADD feature?

 

All 3rd gen 4runners and 1st Gen Tacoma e-lockers are wired the same. Some of the wire colors might be different, but pin placement is identical.

ADD is Auto Disconnect Differential. It doesnt really have anything to do with the e-lockers.

I'm guessing your truck probably is not prewired, so you will need to start from scratch.

 

Why not make your own harness and then not have to deal with all the safety stuff?

 

I mean, this would definitely be the easy way to do it, and I’m becoming increasingly tempted. I’d just like to do it all OEM if reasonable. Are there any aftermarket harnesses that include the proper illumination of the dash light?

I’m fairly certain that there is no OEM pre-wiring in the truck. Although I did find another switch in a storage compartment that has 4 wires coming off it’s harness instead of just two as is the one that came with the e locker.

Does anyone have a picture/diagram of the e locker ECU showing what the pins/wire colors are? These diagrams all seem to just show the ecu without which wires are to go to which pin... then I’d probably be able to figure which ones head towards the rear and which need to find a home up under the front.

 

The diagram I posted tells you everything you need to know

 

You wouldn’t get a alumination on the dash saying it’s working but you get the light on your switch to come on to tell you it’s engaged. This is how I did mine in my taco and in my runner. I can send you pics of the switch if you want. It’s pretty much what you get from 12voltguy but I did mine for about $60

 

Wow yeah that does have more than I saw at first glance! I was thrown off by the harness drawing on the right side. I haven’t found anything that looks like that yet. Everything is double row that I’ve found in mine. Hmm. Do you know what year and model that is specifically depicting? Thank you!

I checked under the driver seat and found a little rats nest of wires. Here’s a picture of that.

 

Hooking up the dash light is very simple. All you have to do is hook it up to the position sensor for the actuator.

The Cluster provides power to all lights on a common 12v rail, and the sensor would complete ground. It's just a single wire.

 

This stand alone, DIY diagram has been around since the beginning of time. Pretty simple stuff.

 

The diagram I posted is from a 97 Tacoma. In the it shows the plug for the integration relay. Think of that as a very primitive body ecu.

That plug in in the back of the dash fuse panel aka, integration relay.

 

Gotcha. I’m going to have to inspect this and compare my findings on my next day off. These last few posts are really starting to clear things up on how I should proceed with entering the world of wiring. Thanks! I’ll update.

 

Wiring is one if those things that you don't rush! Take your time and completely understand what you are looking at. Then you can do something that will work correctly, and be reliable.

I can help if needed. I have wired an elocker (mine) both with a relay and with the OE ECU.

 

Hey Saturday I picked up a drum to drum e locker from the scrap yard off a 2002 Tacoma TRD Auto. I have a 2003 non-TRD M/T. I am now trying to figure out how to wire it up. I also picked up the switch and have an ECU from another TRD I picked up from a yard a while ago when I went to look for the rear and found it gone. Seriously these Tacoma's salvage is seriously sought after in my neck of the woods. The truck came into the yard the prior evening and I showed up just before they opened and was first to the truck. By the time the two hours had past to get the rear and coil overs (TRD Bilstens) most of the interior had been or was being removed as well as the rest of the front suspension. Some guys showed up 20 minutes after me for the locker. I'm glad I showed up when I did. Anyways....

So it appears from the above wiring schematic from COMAtized99 that a good number of the pins are for the e locker or some function/detection indicator for it. So even if one doesn't have an e locker rear the wires are still there for the application. However they don't run back to the diff as there is no locker. Therefore if I run a six wire lead off the e locker harness I can patch into these ECU wires just prior to them entering the ECU much the same as what is shown in this post http://www.sonoransteel.com/phong/retrofit_electric_locker.html. I suspect he doesn't have a 4x4 Runner because he had no ECU to begin with but he did have the some of the wiring. Let it be noted that the box in said schematic labeled 4wd control ECU is not an image of the pin layout in the actual ECU as I first thought. The line exiting the schematic box that represents the wire is numbered just as it exits the drawn rectangle and that number represents the pin #. I only mention that for others reading this who may be confused as I first was. The pin numbering in the ECU can be seen by looking inside the female socket of the ECU. A crude schematic would be this

4 3 2 1
10 9 8 7 6 5

So we are talking Tacomas here so iirc the wires colors should correspond at the e locker harness and the ECU if both are Tacoma birthed. With 4runner the link I provided shows the colors of the wires of the 4runner e locker harness and what pin they correspond to on the ECU. So no matter the differing colors of wires at the ECU, if it's from a Taco or a Runner, you can figure out which to tie it into based on pin #/location. I'm am somewhat surprised that the OP's truck doesn't have it's own ECU being that it is 4x4. Unless the ECU is for e locker equipped vehicles only. Perhaps I misunderstood. OP you should dig up above to see if the plug is up high like in the 4runner in the above link or buried in behind that metal panel behind the kick panel because the ECU harness may have been tucked away back in there from the factory. Anyways....

So I noticed the rear I picked up doesn't have ABS (no harnesses and ABS holes capped off). I was surprised. IDK if TRD came without ABS for whatever reason. I have not pulled the axles to see if the ABS sprockets are there or not. No big deal because I was going to use my axles anyways and I have ABS. I'll just uncap the holes and plug in my sensors. Going to pull the third as well because there is no pinion preload and it has a good bit of slop, rotational play. Never dug into a third member before but in my relentless quest to be locked up I have acquired a good bit of knowledge on the subject. I figured I should freshen it up before install since it's all out and that way I can install solid spacers at the pinion and carrier to avoid the slop from returning. But I digress. Wiring is the point.

 

All elocker axles are setup for ABS, even if the truck didn't have it. You can uncap them and plug your sensors in.

I talk about the wiring here: https://www.tacomaworld.com/threads/tiffany-the-taco.374490/page-5#post-14771682
The colors might be different on yours, but the pin numbers should be the same.

 

Good news! Thanks.