Problems with stock air lockers not locking (mostly front)

[Danarch]

I relocated my air lockers compressors today and I still have problems with the front activating. All air line is new. The rear usually locks and locked today. I am not great at electrical work which doesn’t help. I have a few questions.

1. Will the compressors turn on with the engine off, or does the engine need to be running? How loud are they? I am hard of hearing and wondering if I am simply not hearing them come on. I say this because the rear does lock after a few minutes even though I don’t hear the compressor. Sometimes I need to roll a little bit. I’d like to be able to listen with the engine off. (I suppose an option would be to simply take the hose off and see if I feel any air coming out?)
2. Sometimes when I go activate the front the rear locker light will start flashing again. If I deselect the front the rear dash locker light will usually turn back to solid and engage. (This was happening before I relocated them, so me relocating them didn’t cause it).
3. As noted above I am not good at electrical. I disconnected the plug and probed the connector with the two wires. My meter showed “OL” which I believe stands for open line. Maybe the plugs need to be connected and I need to back probe the plug? If so how many volts should it have?
4. Why does one side of the plug have two wires then other side has three. Then when the wires leave the black casing there are 5 wires total.
5. Since the lockers are air I assume the plug at the differential is to send a signal to the dash light to turn solid it indicate they are locked?

Any thoughts appreciated. I’ll be checking the owners manual and see what I find there.

 

[JKP]

All you need is the key ON. And I'm pretty sure that once you turn the lockers on, the pumps will continue to maintain the air pressure even when the key is OFF. The locker lights flash when the key is OFF if they are engaged.

Did you try S turns to get the front locked?

Turn the lockers on and pull the air lines at the diffs and check for air pressure. Put your thumb over the airline and the pump should cut off at 5 PSI.

The air line inside the diff can come loose, you may have to pull the cover and check. Also, the nipple on the diff can rust out.

The wiring on the diff goes to a switch inside that tells the cluster when the diff is locked. DON'T remove the switch, as you have to pull the carrier to put it back in correctly.

The FSM with schematics is available under Resources.

 

[Danarch]

Thank you very much. I needed to know if the compressors would activate with just the key on.

I did try the S turns and no luck. The last time we went off road the front wouldn’t stay locked then didn’t lock at all. I finally decided to move them up to the engine area and installed all new hose to eliminate a leaking hose.

Thanks, I have the FSM downloaded and will be checking it out.

 

[Danarch]

@JKP thank you. I just went out and turned the ignition to on. Both pumps work and then three wires rear stops pumping pretty fast. The front kept pumping, removed the hose at the pump and placed my thumb over it and it stopped.

I’ll have to crawl underneath and remove from the differential and see if it stops. I doubt the metal inlet is rusted, jeep is pretty rust free, spent its entire life in the general Sacramento CA area.

It should stop when I remove the hose and place my thumb over it as it’s a brand new line. If so sounds like I need to remove the cover and see if the hose inside the differential has come off. If that hose is good then I guess there is some internal problem with the locker assembly itself?

 

[JKP]

If the hose inside the diff is good, it's probably the actuator leaking.

 

[Duck Doctor]

Had the same issue with my LJ Rubicon. Opened the diff cover and figured out that the gear installer failed to hook up the internal hose.

 

[Danarch]

Had the same issue with my LJ Rubicon. Opened the diff cover and figured out that the gear installer failed to hook up the internal hose.

So you just needed to reattached the hose to the gear installer? Or was something wrong with the gear installer? It seems off a hose would simply come off inside the differential. But guess they could work their way loose.

 

[Irun]

It seems off a hose would simply come off inside the differential. But guess they could work their way loose.

Think about it this way. For more than 20 years that small hose, with only a tiny spring clamp, has been sitting bathed in gear oil. I've seen several where the hose was deteriorated and had simply popped off. Let's hope it's not that, because the actuator is no longer available new.

 

[LONGJP2]

Think about it this way. For more than 20 years that small hose, with only a tiny spring clamp, has been sitting bathed in gear oil. I've seen several where the hose was deteriorated and had simply popped off. Let's hope it's not that, because the actuator is no longer available new.

That little pre-formed hose isn't available either.