4wd vacuum system [pure novice confusion]

I have a 2003 5sp 4wd factory supercharged taco. The 4wd doesn’t engage and no lights or icons show on dash.

I have the J style shifter WITHOUT 4wd button but I’m reading those are mechanical and don’t have actuators, but I DO have an actuator. I got new actuator in mail thinking it would fix 4wd then realized I’m missing hoses leading to current actuator. I’m curious if these are “vent” hoses or are these hoses necessary for the actuator to function. I’m completely new to mechanics so forgive my ignorance. I’ll attach photos of diagram where hose is missing and circled the part where hose is supposed to go, which I have not a goddamn clue what part that is

 

If I’m not mistake this is the part I’m looking at. This conjoined hard segment of a thick tube and thin tube. Neither have hoses. This is the first hard segment leading away from the actuator. I have no clue where the thin vacuum line is supposed to go from here. Or even if these are vent lines and don’t matter anyways. Both the thick and the thin lines are gone from here

 

While on the hunt for the vacuum hose location I found this area where it looks like I’m missing a system from. Also right next to it looks like they cut a hard tube and pinched it/rolled it up to cap it.


My buddy is thinking the previous owner removed the vacuum system because they wanted it to be super pre runner -_- the eLocker works tho so Atleast 1 vacuum pump is still on here

 

That hose on the actuator is just a vent hose, the one in the lower picture that is crimped off is a brake line.
The later first gen front axles are electronic, weather or not they have the electronic transfer case.
I'm not well versed on how the first gen system works but looking at the wiring diagram it appears to be similar to the 2nd gen in that it uses a module and a series of limit and detection switches to operate and determine the position of the actuator(s).
Below is all the information I can find on the system.

 

Dope man thank you very much!! Gonna read all these RN and try to get this problem resolved tonight !!

Now knowing that the hose isn’t a vacuum and it can function without it , I wonder if this helps narrow the issue back to maybe being a failed actuator? I heard the internal motor looses connection easily, and I jump my truck and shit on it really hard so I can easily see how the internal motor could of lost its sauders inside !! The actuator is a really tight fit in there do you know if you have to take off the rack and pinion to remove the actuator or I can get it off without additional disassembly of other parts ??

 

DUUUDE those pdf’s help me a lot thank you very much man!! I’m gonna go and start by checking the outputs on those terminals with the add harness !!

I’ll post my findings

 

It's not a vacuum line but it needs to stay connected to keep dirt and moisture out of the actuator.
The actuator looks similar to the one on 2nd gen trucks but I can't say weather or not it is the same internally or what it takes to remove it.
2nd gens can be removed without removing anything else but I have no idea if first gens can be or not.
I've done alot of research on the 2nd gen system and have a complete writeup on it but I haven't really looked into the first gen system although looking at the wiring diagrams it looks like it operates very similar.

 

So you are looking at part of the factory brake tubing. The 90 that is circled is the factory 90 that came from the master cylinder and went to the rear brakes. The 90 to the left is for the front brakes.(I think) The brake line that has the coils in it should go to the front port of the master cylinder. That system has been heavily modified.. Do the brakes feel ok?

 

If you get a chance, Take a photo of the brake master cylinder, but angle the camera so that you are looking down from the top of it.

 

Yeah the brakes are currently good!! I recently had a camburg hand break which locks up the rear brakes only so i wonder if the installation of that system led to the fuckery of this stock system being cut up and removed !!

 

what setting on this meter should I use while checking the flow of electricity in the harness?? I am oblivious to electric/mechanical engineering currently, BUT IM WORKING ON IT TO GET VERSED

 

That would explain it.

 

I knew those were brake lines but I wasn't sure how they belonged, I don't get to work on Toyota's in the wild much.
I've spent more time researching things and testing on my own truck trying to help people here than I have working on them in the shop lol.
That's why I spend most of my time in the 2nd gen section, I don't have a 1st or 3rd gen to look at and experiment on.

 

This brake system has definitely been modified, more than once. It looks like a lot of that stuff can just be taken off. It isn’t doing anything anymore.

 

Red circle for checking voltage/Blue circle for checking resistance/continuity.

 

Your dead on point with the actuator. The most likely issue is water in the front actuator. The second gens were known for it, especially if the vent hose was broken.

 

Yea I've spent hours researching the 2nd gen 4wd system and determining what makes it tick as it seems to intimidate alot of people and it seems water in one or both of the actuators from a broken vent hose is the number one cause of problems.
Another common one is a bad ground that seems to be between EE on the back of the cylinder head and J/B No2 based on data from trying to help people resolve it, I haven't tracked down where it goes bad though as people always give up or disappear before we get there.
I'm actually in the middle of chasing that with someone right now, not sure if they are gona come back or not.
https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/page-12

 

Inside the actuator plug all the resistances look appropriate! I’ve been looking for the ADD relay behind the glove box box but not finding it. I found the transmission relay behind the kick panel on the passenger side though. I read on one of these forums if you have a truck w/o the 2-4 button, there is no ADD relay and only the transmission relay. hmm I’m not positive if my truck actually has the ADD relay or not , maybe it just has the transmission relay. ‍♀️

on a positive note though I found an upgrade I didn’t even know I had!! This UDR calibration box

 

Here’s the transmission relay box behind the kick panel on passenger side hmm I wonder if this is the only relay associated with ADD or if I do truly have an ADD relay behind the glove box somewhere 0.0

 

And if water damages the ADD, that would make entire sense because I sent my truck through a wash with 3ft high water about an hour before getting stuck in the sand and discovering that my 4wd didn’t work and spent 3 hrs trying to get my 2wD, non-locking diff truck out of the sandy wash