Home brew diff lock ECU for air lockers

[landcrshr]

When I looked into air lockers I saw this ARB demo video where the guy looked like he was playing dashboard piano when he went to operate those big switches. I thought, no....Toyota got it right with the single rotary switch. But how would I integrate it with the OBA system and maintain the factory behaviour?

Got the EWD and started tinkering, here's the prototype:



Here's what it does:
1) Integrates the factory wiring, switch and lamps with the OBA system.
2) Diables solenoids until the center is locked (this feature provides compressor isolation.)
3) Flashes the lamps to indicate a prohibited operation.
4) Maintains factory appearance.

What it does NOT do:
1) Provide a maximum speed inhibit (maybe on version 2.0)
2) Act as a drop-in replacement for a factory E-locker system.
3) Save you money.

I will be happy to provide details.

 

[TEXASYETI]

This is cool. More please...

 

[chap79]

There's a few write ups for this floating around.

Here's one.

arb-air-locker-factory-switch-integration

 

[landcrshr]

There's a few write ups for this floating around.

Here's one.

arb-air-locker-factory-switch-integration

Thanks, checked out the link. WOW! A Whoping five relays and it still uses the ARB compressor switch.

With clever wiring you can have compressor isolation, CDL interlock and no additional wire looms inside the vehicle.

The electronics you see on mine is only a timer to flash the lamps when the center is not locked (just like factory.)

 

[landcrshr]

More Pics

Modified ARB loom ties into the factoy harness in the engine bay. I used an Amphenol connector, but any six pin (15A) connector will do.


Adjustable pressure switch is used on the solenoid output to illuminate the indicator lamp. (If the air line ruptures, the light goes out!)


View of the solenoid, tee and pressure switch.

 

[Douglas S]

Very nice! I have factory lockers, but if I didn't I would be all over this.

 

[86tuning]

Looks good! I like your pressure switch-light setup.

Any problems with vibration? I know that on race cars with oil fittings cantilevered out like that we get oil leaks. But an engine has a lot more constant vibrations than the compressor would, as engines are constantly running.

Can't wait to see your diagram of how it all works. I'm sure you could sell a bunch of kits if you wanted to put them into production.

 

[landcrshr]

Looks good! I like your pressure switch-light setup.

Any problems with vibration? I know that on race cars with oil fittings cantilevered out like that we get oil leaks. But an engine has a lot more constant vibrations than the compressor would, as engines are constantly running.

Can't wait to see your diagram of how it all works. I'm sure you could sell a bunch of kits if you wanted to put them into production.

Yeah, you noticed the cantilevered issue that I thought might be an area of concern. It's all solid, plus the compressor mounts to the cruise control bracket, which is damper mounted. So far it's OK after 130 miles off-road, but we'll see this spring when I hit the washboarded roads of Death Valley.

Thanks for your input.

 

[landcrshr]

ECU diagram

Here's the diagram, excuse the napkin-sketch quality:

View attachment Diff-lock ECU.pdf

 

[landcrshr]

Simple Version

The most basic version of this can be seen here (no status lamps).
https://forum.ih8mud.com/80-series-tech/687858-air-locker-control-made-super-simple.html

 

[alia176]

I love complicated s*** like this!!! Nice job dude.

 

[landcrshr]

I love complicated **** like this!!! Nice job dude.

Thanks, IMHO it is simple to install. I just didn't see the use in running an extra harness through the firewall when there was already one there.

After I get the front locker in I might work on figuring out how to add a speed inhibit for safe measure. Then it'll get complicated!

 

[azTony]

I would like to be able to lock the front only or the rear only

 

[ironhippy]

This is great.
I am hoping to use some micro boards to eliminate some of my need for relays.
I have a bunch of relays wired in succession to provide logic for my switches.

I would like to see more details of exactly what your board is doing. You mentioned this is a prototype, are you planning on producing any for sale?

 

[alia176]

I would like to be able to lock the front only or the rear only

The factory dial makes that a difficult thing to achieve. However, I wanted independent locking at first, but after a while didn't mind having the rear locked, and then the front. At least I haven't found a situation where I only wanted the front locked and not the rear. Admittedly, having a part time T case does make things different than a full time rig.

 

[LandCruiserPhil]

The factory dial makes that a difficult thing to achieve. However, I wanted independent locking at first, but after a while didn't mind having the rear locked, and then the front. At least I haven't found a situation where I only wanted the front locked and not the rear. Admittedly, having a part time T case does make things different than a full time rig.

Just interrupt the signal to the rear locker from the dial with a switch to the left of the magic dial.

With a part time t-case ground pin 15 and you have full control of lockers

 

[sleeoffroad]

This is really nice. If the board becomes production it would be really nice for shops to use to reduce install times.

As for front only, I would not do it with that "mini-truck" front diff. They are marginal in the best of cases for heavy 4wheeling, not lock that and not the rear and it won't last very long. Also can't say I have ever been in a situation where that would have helped. Now if you are in a buggy and can do front diggs, that is a different story.

 

[LandCruiserPhil]

This is really nice. If the board becomes production it would be really nice for shops to use to reduce install times.

As for front only, I would not do it with that "mini-truck" front diff. They are marginal in the best of cases for heavy 4wheeling, not lock that and not the rear and it won't last very long. Also can't say I have ever been in a situation where that would have helped. Now if you are in a buggy and can do front diggs, that is a different story.

I have found front locker only helpful in a off camber low traction situation where you do not want the axle crab walking down. Like up and around passing a tree, your approach is off camber low traction lock rear first get your front axle past then lock front unlock rear to bring your rear axle up the low traction approach section without crab walking into the tree.

 

[alia176]

Just interrupt the signal to the rear locker from the dial with a switch to the left of the magic dial.

With a part time t-case ground pin 15 and you have full control of lockers

Exactamundo

Just a feedback to the OP regarding the control of the air compressor. Your logic makes it so that the air comp turns on AFTER you engage the front the rear locker and the CDL is locked. While this is fine for a dedicated compressor for locker(s) activation only, it may not take into account other situations. Some of us have higher output compressors and would like it to run w/o having to activate the lockers (for inflations, running tools, making margaritas with the blender ). So, in that case having the OBA separate from the locker activation logic seems warranted.

 

[landcrshr]

Exactamundo

Just a feedback to the OP regarding the control of the air compressor. Your logic makes it so that the air comp turns on AFTER you engage the front the rear locker and the CDL is locked. While this is fine for a dedicated compressor for locker(s) activation only, it may not take into account other situations. Some of us have higher output compressors and would like it to run w/o having to activate the lockers (for inflations, running tools, making margaritas with the blender ). So, in that case having the OBA separate from the locker activation logic seems warranted.

Leaving the center UNlocked does alow the compressor to run for other uses. Compressor activates when the switch is first turned to the RR position.