Need Help with my ELD Swap

[DGE1993]

I am currently swapping in a factory rear ELD into my base model (Non-Sas) 2-door. I plan on wiring the locker off of my AUX switches, but after reading every thread I can find on the swap, and a page out of a factory service manual I found online, it appears that initial power is sent to the diff. and then reduced to save wear and tear on the solenoid.

I am looking for someone who either has access to Fords tech specs and can find me the exact voltages that are sent to the diff. or someone who is willing to craw under their Bronco with a factory ELD to back-probe the connector and measure the voltage for me.

Who here is wiling to be the hero us Non-Sas guys need? This is the final step in my swap, and I would like to have all the info before I do a write-up for the rest of the guys wanting to also do this.

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[DGE1993]

Some Info I have found so far.

(From a service manual I found online.)

From the thread: M220 E-Locker Differential Deep Dive Overview ( https://www.bronco6g.com/forum/thre...dive-overview-skip-if-youre-tldr-prone.41973/ )

 

[Bmadda]

This post piqued my interest, so I did a little testing. BU/OG is + and GN/BN is -. If you were wiring it yourself that wouldn't matter, but for testing the OE system it does. 1st, to check i had backprobes in correctly, and because I know my locker works, I checked resistance key off:

Next I started it in 4H normal, and turned rear locker on. I still had my DVOM under the vehicle and it took me a bit to raise it back up, but when I got back there it read this:

Next I went and found some longer test leads so I could see what happens from the driver's seat:

Next I watched for it to drop to around 7V like it had before. It did, but it took what seemed to me like quite a while:

Next I decided to try to time the "event" on my phone. It was awkward trying to start the timer and press the button simultaneously, so I started the timer a little before, and had a little reaction lag after...I would guess the correct time would be 30 seconds:

 

[DGE1993]

Holy. Crap. You sir @Bmadda went above and beyond what I was looking for. I have spent the last three hours searching Ford's tech service site for that exact info to no avail. If it wasn't such a long drive from Missouri to Wisconsin I would buy you a couple packs of beer!

 

[orion]

There have been multiple people who have wired directly to the AUX switches, including myself, with no ill effects. I wouldn't worry about the step down voltage. Someone somewhere also bench tested one and left the locker locked and didn't find any measurable heat differences after a while, hours from what I remember. I looked into all of this when I did my front locker and the only thing I would suggest is if the AUX switch you use isn't 10 amp fused, change it to a 10 amp fuse. That is what all the aftermarket harnesses and Eaton's harness has.

 

[Bmadda]

Holy. Crap. You sir @Bmadda went above and beyond what I was looking for. I have spent the last three hours searching Ford's tech service site for that exact info to no avail. If it wasn't such a long drive from Missouri to Wisconsin I would buy you a couple packs of beer!

It just so happened that my Bronco was in the shop on the alignment rack when I read your post! We had a pretty good snowstorm today, so I came in to work to plow the lot. I parked the Bronco inside so it would be out of my way while plowing and it was still sitting there when I took a break for lunch! I agree w/ @orion above that the unit will probably work just fine on switched B+, but your original question was in fact completely correct! I have been pondering how to convert some of these features to full manual control, because we have seen computer errors happen on the trail and get folks stuck. Fun to learn!

 

[DGE1993]

I spent most of the day wiring it up to my Aux switches like you guys suggested. I still might come up with a way to step it down like the factory ELD does, but that will be down the road a bit if I seem to have issues.

I was mainly concerned that this being the first modern truck I've worked on, the ELD wasn't going to be a simple 12v system. I was able to gain access to Ford's Tech website, but they never listed any specs on voltage to the diff.

I still appreciate the info you guys provided me.

 

[Bmadda]

I spent most of the day wiring it up to my Aux switches like you guys suggested. I still might come up with a way to step it down like the factory ELD does, but that will be down the road a bit if I seem to have issues.

I was mainly concerned that this being the first modern truck I've worked on, the ELD wasn't going to be a simple 12v system. I was able to gain access to Ford's Tech website, but they never listed any specs on voltage to the diff.

I still appreciate the info you guys provided me.

Another possible reason they step down the voltage is "residual magnetism" it may be a little more difficult to get the locker to unlock instantly if running on switched B+. Won't hurt it at all, but might stay locked after you shut it off, till you backup, go forward, move around a bit. That may be why they did it this way. I have aftermarket ELDs in my YJ that are that way. They lock fine, but don't wana unlock right away

 

[DGE1993]

That's a good point @Bmadda. For the amount of time I will probably use the locker I don't think it will be to big of issue. Most of the trails around here are off of forestry roads, so I have quite a bit of dirt road driving before a I hit pavement. That is, as long as I remember to turn it off when I leave the trail.

 

[climb2descend]

For the aftermarket Eaton e-locker install they don't drop the voltage down. Seems like just a Ford thing. Circuit with their harness is at last sheet.

https://www.eaton.com/content/dam/e...ocker_Installation_Instructions_July_2004.pdf

I've been mulling this swap myself but man trying to get rid of a whole stock axle after seems sucky lol. But this does seem like the most efficient and cost effective way to do the swap and keep the 4.46 gear ratio.

Looking forward to your write up!

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