I have searched and read many threads on this issue but I am looking for some specific help if the likes of engineer1 or antman are willing to offer some advice to a newb. I've been on the forum awhile but am just beginning my foray into diy repairs and mods.

I currently have the front dif actuator removed and function tested, this is where I am stuck. Feel free to post here or pm me with advice.

Thank you-

Justin

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Oh my...
You are a novice and you decided to remove the ADD? What were your symptoms?

What was the truck doing before you took it apart?? Why did you decide to remove the actuator? What are you trying to do (give more detail than "trying to make it work ")?

Yes sir, thanks for the reply. The add removal seemed straightforward enough so I decided to tackle it. The four wheel drive would not engage when moving the lever to 4-hi. No light on the dash, no blinking light, and no engaged front dif. When in 4-hi the transfer case does lock the front drive shaft but I get nothing beyond that. Same situation in 4-Lo.

@Muddy duck I went with the add based on the symptoms I was having. Perhaps there were other checks to do before this stage.

Electronic vs Manual 4wd try this link @Hambone . Actually read the link that is in the post I linked on ADD. This should help you troubleshoot and check the ADD too.
When you shifted into 4hi were you moving? When was the last time you used 4wd?

Sounds like you are somewhat on the right track with the ADD...

BUT... no flashing light makes me think it is something further back in the transfer case. There is a sensor that picks up the TCase being engaged, that lets the 4wd ECU trigger the ADD. I would guess your problem starts there.


You need Help from.
@BlackWorksInc

And just a hint, from years of troubleshooting. Start with all the upstream stuff first that can be easily tested without taking anything apart. Dig in only after all the input signals look good.

Check the fuse. should be a 20 amp if memory serves correct. @Hambone
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yup walked outside, 20 amp fuse. the inside box located above e-brake pedal. I had a few come in with that same blown fuse before.

@1engineer , Thanks for the link. I actually had read that prior to tackling this project.
My symptoms:

Moving the transfer case lever to 4-hi would result in no flashing light or activation of 4 wheel drive. This was done at speeds less than 50 mph, in drive and every variation in between.
Moving the transfer case lever to 4-low when stopped and in neutral; I could feel the lever engage the gears and the truck would drive as if in low gear but no lights would illuminate on the dash and the front dif would not engage.

With the transfer case lever in 4-hi, the front drive shaft is locked in place and will not free spin by hand. The same is true when placed in 4-low with the transmission in neutral.

I checked the 20a fuse for the 4wd under the driver side dash as well as the two fuses under the hood in position 30 and 31.

Reading the FJ post led me to check the ADD, ohming out the motor with the ADD still attached gave me no reading between pins 1 and 2. This led me to believe either the motor is bad, or the posts became disconnected. Thus I removed the ADD after draining the front dif fluid.

Once removed, I took off the black housing held in place with 5 phillips head screws to reveal the motor and gears. Everything looked great with clean grease and the contacts still intact. I tested the ADD and verified the worm gear operated in both directions when 12v was applied.
I reassembled the ADD and again tested the motor, the fork moved in both directions.
I again ohmed out the motor with pins 1 and 2 showing open and pins 1 and 3 generating a reading.
The vacuum release tube appears to be solid from the ADD to its point of termination.

This is where I am stuck, do I reinstall the ADD and fill the dif just to try it out?

No vacuum involved in Toyota's ADD, that is probably a breather line.

My money is on the transfer case position switches, as @wfo9 mentioned. No 4wd dash lights at all point to the 4wd ECU not knowing it is in 4wd.

Yes sir, my mistake. It was the breather line. Are the transfer case switches something I can check?

Yea, it seems like the only logical answer, but I would wait on BlackWorksInc to chime in. He may have some troubleshooting guides.

According to the repair manual.... You have to remove transfer case and transmission to get at the indicator switch. (I think it is on the top of the T-Case). You would want to be be 100% sure that was the problem before going there.

This may help if you can reach the connectors...

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Thanks gentlemen! I will also await @BlackWorksInc to offer some advice if he can.