Hacking the magic dial to engage only the front locker (1 Viewer)

[ThreeEyedBandit]

Tricking the ecu might would be simple, just need to source a 4pdt switch. Your first position on the dial could be selectable, front or rear locker depending on the new switches location. Second position would be both locked. Pretty sure the indicators would be un-happy.

I'll see if i can finda a local(@retrofive) that'll let me peer into their lpcker ecu to see what can be done. I would find it strange since the locker ecu has sepeate independent inputs that there isn`t a way around it. I'll report back my findings in a couple of days hopefully.

 

[landtoy80]

After thinking, I have a way that might work.
Put a switch on the power wire to the front diff where you can turn on and off the power to the front actuator. If there are two wires to the actuator where one locks the diff and other unlocks the diff, put the switch on the one that unlocks the diff. Leave the switch on, turn the F/R diff lock switch to lock front and rear diffs. When you want to unlock the rear you first flip the switch you hooked up to the front actuator then turn the F/R diff lock switch unlock the rear. The rear will unlock but the front will still be locked. Should be that easy.

 

[nukegoat]

After thinking, I have a way that might work.
Put a switch on the power wire to the front diff where you can turn on and off the power to the front actuator. If there are two wires to the actuator where one locks the diff and other unlocks the diff, put the switch on the one that unlocks the diff. Leave the switch on, turn the F/R diff lock switch to lock front and rear diffs. When you want to unlock the rear you first flip the switch you hooked up to the front actuator then turn the F/R diff lock switch unlock the rear. The rear will unlock but the front will still be locked. Should be that easy.

The lockers don't work that way. Dc motors. I think the ecu just reverses polarity to unlock.

 

[landtoy80]

Then wouldn't a switch on the single wire would do the job?
If when you turn the F/R diff switch to unlock the front and rear diff but power cant get to the front diff the front diff will still be locked.

When the diffs are locked and turn the motor off, the diff locks don't unlock do they?
When the key is in "on" position and you turn the F/R diff lock switch you can hear the actuator motor run for a second then stop. If the actuator cant get the signal to unlock or run the actuator backwards, it wont unlock the diff.

Putting a switch on the front diff actuator would be no different than locking it then unplugging the actuator.

 

[Robkc]

My rear actuator isn't working at the moment. When I turn the switch to lock both front and rear, the front locks up, the light for the rear just keeps on flashing. So on a '95 at least, the black box does not seem to care if the rear is locked or not before engaging the front.

As JeepinPete stated: As long as the locker ECU is trying to send signal to rear locker and you turn Magic Dial to lock front as well, front will lock independently of status of rear locker. Add a switch that will disconnect power to correct wires of rear locker harness. It is a DC motor and the ECU reverses polarity to lock or unlock. Green wire and Green w/ Lavender in harness section closest to Rear Diff according to page 153 of the 1996 EWD made possible by BirfMark.

Would be same result as if the rear locker didn't lock. You will have visual confirmation as a separate signal from the rear locker status switch gets independent power and will continue to flash on the dash.

 

[bloc]

OK, so interrupting the signal to the rear before it locks but not interrupting the front is a way to accomplish this..


How about a way to UNLOCK the rear but not the front? Another switch to interrupt the front locker motor? Or are things getting complex enough that it's better to just unlock everything then re-lock only the front using the method discussed earlier?

When people in this thread mention the ECU only trying to lock the front after it has done so for the rear, but that it will lock the front before the rear is actually locked and the position indicator tripped (dash light flashing).. are we assuming the ECU will only activate the front control relays after it has successfully done the rear? From reading the EWD there are three position sensors in each diff.. two to indicate motor and spring position (one for each end), and one for the fork itself. So technically the ECU knows whether the locker actuator has been thrown even if the locker hasn't fully engaged yet.

Do guys with corroded actuator motors in the rear still get front locker activation successfully?

 

[ThreeEyedBandit]

OK, so interrupting the signal to the rear before it locks but not interrupting the front is a way to accomplish this..


How about a way to UNLOCK the rear but not the front? Another switch to interrupt the front locker motor? Or are things getting complex enough that it's better to just unlock everything then re-lock only the front using the method discussed earlier?

When people in this thread mention the ECU only trying to lock the front after it has done so for the rear, but that it will lock the front before the rear is actually locked and the position indicator tripped (dash light flashing).. are we assuming the ECU will only activate the front control relays after it has successfully done the rear? From reading the EWD there are three position sensors in each diff.. two to indicate motor and spring position (one for each end), and one for the fork itself. So technically the ECU knows whether the locker actuator has been thrown even if the locker hasn't fully engaged yet.

Do guys with corroded actuator motors in the rear still get front locker activation successfully?

Yes, the front locker doesn't care if the rear is locked. Corroded or working. They both try and lock at the same time independent of each other.

 

[Robkc]

OK, so interrupting the signal to the rear before it locks but not interrupting the front is a way to accomplish this..

Yes

How about a way to UNLOCK the rear but not the front? Another switch to interrupt the front locker motor? Or are things getting complex enough that it's better to just unlock everything then re-lock only the front using the method discussed earlier?

If you want simple yes just use the magic dial as originally designed then flip interrupt switch and magic dial as described previously.

When people in this thread mention the ECU only trying to lock the front after it has done so for the rear, but that it will lock the front before the rear is actually locked and the position indicator tripped (dash light flashing).. are we assuming the ECU will only activate the front control relays after it has successfully done the rear? From reading the EWD there are three position sensors in each diff.. two to indicate motor and spring position (one for each end), and one for the fork itself. So technically the ECU knows whether the locker actuator has been thrown even if the locker hasn't fully engaged yet.

The magic dial position tells the locker ECU which locker motors to attempt to move in which direction.
The limit switches tell the ECU whether the fork has moved to the limit of travel and to cut power to motor drive. Modification described above accomplishes this same thing.
The status switches tell the ECU whether to flash or solid display of corresponding bulb in dash for visual feedback to driver of locker status.
My rear diff lock bulb is currently burnt out and I can lock/unlock and know by behavior of truck. I have just been too busy to dig in to the dash to replace at the moment.

Do guys with corroded actuator motors in the rear still get front locker activation successfully?

Yes

 

[cybrstar]

sorry to open up an old thread but....

I'm having an issue with my front locker. It blinks when I try to engage it, center and rear is fine. Rather than me looking to all wiring possibilities that can fix my locking/unlocking, reading this tread gave me an idea to bypass the locker ecu all together (only for the front to work independently from the complete system and asked in this thread).

Everyone knows of the front locker 9volt trick. Apply positive voltage to pin #3 and negative voltage to pin #2 to lock the diff, and visa versa to unlock.

So.........

To run the front locker independently and bypassing the complete LOCKING OEM ECU system (yes disconnection of the harness at the front locker and running new wires to the actuator)

Why not run a positive wire and a negative wire to both PIN number 2/3 and CONNECT to a switch of some sort to reverse polarity to lock and unlock (maybe a relay for 1 switch method), or even 2 switches to reverse polarity independently (#1 switch sends pos voltage to #3 and neg voltage to #2 to lock, and #2 switch sends Neg voltage to #2 and Pos voltage to #3 to unlock). You would need to have control of the switches because leaving the power on either way too long can burn up the motor. So the switch might even be better if it were a push button style that would only activate for 2 seconds, which is more than enough time to set the locker in either way. This method would supply power the actuator in the direction of locking and unlocking independently as we do with the 9 volt actuator test but using the 12 volts that any acc wire can provide. Better I hear if you can regulate it to 9 volts because 12 volts can over run the actuator and cause some sort of spring tension problem.

Just a thought and any other people run the front or rear lockers independently?

 

[Broski]

Did anyone get this to work if so what method did you use.

I would like to make this happen.

Thanks

 

[landcrshr]

Did anyone get this to work if so what method did you use.

I would like to make this happen.

Thanks

Here's a thought, get ahold of a CDL control relay and use that to independently control the locker of your choosing.

 

[nukegoat]

Did anyone get this to work if so what method did you use.

I would like to make this happen.

Thanks

I never bothered. But I always lock front before rear

 

[LandCruiserPhil]

Interrupt the power to the rear actuator when selected and provide a false signal to the ECU showing the rear has locked. All can be done using a DPDT switchable relay or switch.

 

[Broski]

I never bothered. But I always lock front before rear

On your wonton swapped axles, no ?

 

[Broski]

Interrupt the power to the rear actuator when selected and provide a false signal to the ECU showing the rear has locked. All can be done using a DPDT switchable relay or switch.

Phil have you actually done this.
The issue I see is having to turn the front locker off to get the rear locked.

 

[mudgudgeon]

Build your own control module with some relays.
You can mimic the ecu function, but without the rear needing to be locked first.

There's diagrams floating around the net.

I did this when I retro fitted lockers into my 105series specifically so I could lock the front independently.

I found it useful quite often, and only blew up one birf doing a front dig to help get out of a really s***ty situation.

 

[Broski]

Build your own control module with some relays.
You can mimic the ecu function, but without the rear needing to be locked first.

There's diagrams floating around the net.

I did this when I retro fitted lockers into my 105series specifically so I could lock the front independently.

I found it useful quite often, and only blew up one birf doing a front dig to help get out of a really s***ty situation.

I'm leaning towards the 12 volt Guy stand alone harness for the front only.

At $145 shipped seems like the easiest way to go.

Not worried about the birf's as I run RCVs

I have some concerns about the the third as I'm on 39s Ha ha

 

[Fj80Ringo]

I'm leaning towards the 12 volt Guy stand alone harness for the front only.

At $145 shipped seems like the easiest way to go.

Not worried about the birf's as I run RCVs

I have some concerns about the the third as I'm on 39s Ha ha

Is the 12 Volt Guy still in business. His FB page is old as all getout and his new 12voltguy.net web page seems to be hash too. I am retro fitting two locking diff's in the very near future. I am considering building my own harnesses for them if I cant get one from 12 volt guy.

 

[Broski]

Yep I was never able to get a hold of him.

 

[cody c]

So, what is the circumstance or situation where this has value?
It seems to be just a knick-knack for an "in-case" situation.

Trying to understand.. Doesn't seem to be much value other than in a situation when your going straight ahead, and a locked rear should hurt in that situation anyway.