4x4 Issues, Front diff actuator or t-case actuator?

I'll have to take a look tonight when I get time, if you could fill out 2H and 4H sections of the pin voltage chart in the thread I have linked and post it here that would help me see where everything is and where we need to check first.

 

I have it written out but for some reason it won’t load the picture. The only 2 reading that are off is tl1 and tl2 which read as they would if it was still in 2wd
So after reading more i believe it to be the inside readings of the transfer case actuator not reading properly

 

So TL1 & TL2 aren't changing but 4WD is correct at 12v in 2wd and 0v in 4wd?

 

The voltages are not changing, and staying correct for 2wd. Even though the transfer case is shifting to 4wd

 

So 4WD is switching like it should?

 

Yes it is changing,

 

Very odd that both TL1 and TL2 aren't changing at all being we know the actuator is moving, I would expect at least one to change.
In any case we need to check circuit integrity, unplugh the Transfer Case Actuator and verify they both go to 12v then use a small paperclip or other suitable tool (no larger than the male terminals) to jump them each to Pin 4 (White/Black) of the actuator connector one at a time and verify they go to 0v at the ECU when jumped.
TL1 is Pin 5 (Blue/Yellow) and TL2 is Pin 6 (Blue/White) at the actuator connector.

If that checks out then the issue has to be with the contact plate in the actuator.

 

I already had the actuator out of the truck earlier and sanded down the contacts, and regreased it.
Just went out to the shop to try your suggestion and decided to re check the values. I apparently fixed tl1 and 2 with my sanding, but still flashing on the dash.
ADD is reading 11.9 in 4wd, and it seems that it was probably reading that before. (Had to wiggle the probe around to get a reading, guessing I took the 0.0 for granted before)
Is the ADD reading from the detection switch in the actuator?

 

So now the only value that is incorrect is ADD?
Are DL1 and DL2 correct?

ADD is the ADD Detection Switch in the ADD Actuator on the front axle, it's the feedback for the physical position of the axle disconnect (open (12v) when disconnected (2wd) and closed (0v) when connected (4wd)).

 

Yes dl1 and dl2 are reading correct, although dl1 is only reading 11.8

 

So the actuator is moving at least some.
Have you checked if the front axle is locked in when in 4wd?

 

The actuator is moving the whole way. Im guessing that little switch is bad. Had the add actuator out to manually engage 4wd at the dunes a couple weeks ago.
that little arm had popped out but i put it back together. Then when i was doing my testing it took me to the back, I guess it was both

 

You can check circuit integrity the same way, jump Pin 3 (Light Green/Black) to Pin 4 (White/Black) and verify ADD goes to 0v at the ECU.

If the circuit checks out and the axle is locking but ADD isn't switching in then the issue is likely in the ADD Actuator.

 

Yep wiring checks out, 0v when jumpered. Gonna get a new actuator and see if i can find a used add someone has laying around to use parts to rebuild a spare.
Thank you for the help, i was headed down the wrong rabbit hole for a minute there.

 

There's probably quite a few good ones that end up in the trash with the shotgun parts method of troubleshooting so many people do.

No problem
That's why I took the time to take a deep dive into how the system works to develop a test plan that gives us a very good shot at finding the problem component (or at least having enough evidence to take something apart to inspect) on the first go rather than taking apart/replacing components and hoping you got it right.