Diff lock hack
Senior Member
Joined: May 2016
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From: Seattle, WA
Originally Posted by KingDeleted
It can be done, isolate the wires from the rear end pitail. Cut them and run new wires to a switch, give it 12 volts and you’re golden. That’s what I did
There is probably some off the shelf module you can buy that would replicate the pulsed signal, and then you can chop up the widening harness and bypass the module that the factory setup uses.
Senior Member
Joined: Apr 2018
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I believe from my research a while ago that the E-locker in the differential was expecting a pulsed signal, so 12v DC at some repeating interval. I'd be worried that using constant 12v DC would burn up the solenoid that Ford uses.
There is probably some off the shelf module you can buy that would replicate the pulsed signal, and then you can chop up the widening harness and bypass the module that the factory setup uses.
There is probably some off the shelf module you can buy that would replicate the pulsed signal, and then you can chop up the widening harness and bypass the module that the factory setup uses.
5 Year Member
Joined: Apr 2013
Posts: 6,135
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From: New Orleans, LA
Hey all. Trying to figure out a way to have the diff lock stay locked above 20mph. I found this but they can't tell me if it'll function the same on the F150, just F250/350. Anyone gotten in there yet?
https://www.spediesel.com/pages/instructions
I say "make" lightly because based off the instructions, it appears to be just a $5 relay, couple inches of wire & cheap wire terminals.
I believe from my research a while ago that the E-locker in the differential was expecting a pulsed signal, so 12v DC at some repeating interval. I'd be worried that using constant 12v DC would burn up the solenoid that Ford uses.
There is probably some off the shelf module you can buy that would replicate the pulsed signal, and then you can chop up the widening harness and bypass the module that the factory setup uses.
There is probably some off the shelf module you can buy that would replicate the pulsed signal, and then you can chop up the widening harness and bypass the module that the factory setup uses.
Wayne
Last edited by Z7What; Mar 13, 2019 at 06:54 AM.
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Joined: Jun 2018
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I believe from my research a while ago that the E-locker in the differential was expecting a pulsed signal, so 12v DC at some repeating interval. I'd be worried that using constant 12v DC would burn up the solenoid that Ford uses.
There is probably some off the shelf module you can buy that would replicate the pulsed signal, and then you can chop up the widening harness and bypass the module that the factory setup uses.
There is probably some off the shelf module you can buy that would replicate the pulsed signal, and then you can chop up the widening harness and bypass the module that the factory setup uses.
Senior Member
Joined: May 2016
Posts: 458
Likes: 97
From: Seattle, WA
Geez, you guys call me out and have no faith! At least I was able to back it up this time 
From the Factory Manual, Section 205-02A:
Or
If someone has access to a truck with the locker and to an oscilloscope we can determine exactly what the truck is doing.
From the Factory Manual, Section 205-02A:
When the ELD is engaged, the TCCM sends PWM voltage to the ELD field coil located in the differential. This voltage is initially 98% duty cycle, and then tapers off after 30 seconds.
When the ELD MSS is engaged to lock the rear differential, the TCCM sends a PWM signal to the ELD field coil through the differential lock control circuit. This PWM signal is initially 98% duty cycle to lock the differential and then tapers off to a lower duty cycle once the differential is locked.
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Joined: Jun 2018
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Sorry if it came off wrong, just wanted some data is all. Most decent multimeters have a duty cycle setting. Maybe Ill get bored and crawl down there this weekend get some readings.
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Joined: Nov 2017
Posts: 6,637
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From: Washington
That's a pretty typical way to get a fast response but save energy and wear. Too bad they don't tell what the lower duty cycle is. You could probably use a fuel injector driver to match it.
"Quote:
When the ELD is engaged, the TCCM sends PWM voltage to the ELD field coil located in the differential. This voltage is initially 98% duty cycle, and then tapers off after 30 seconds.
Or
Quote:
When the ELD MSS is engaged to lock the rear differential, the TCCM sends a PWM signal to the ELD field coil through the differential lock control circuit. This PWM signal is initially 98% duty cycle to lock the differential and then tapers off to a lower duty cycle once the differential is locked"