Intermittent Issues Engaging and Disengaging 4x4

I went to turn the 4x4 dial to 4H today and nothing happened. No light and no 4x4 engaged. I tried it a couple more times then it finally engaged and then I engaged 4Lo fine. Later, I went to disengage 4Lo (4Lo to 4H), but again no change in lights. It still read 4Lo and nothing blinking (and still in 4Lo). Tried switching the dial back and forth a couple more times and it finally disengaged.

Got it home and tried engaging and disengaging 4x4 over and over again. It works fine about 9/10 times, but then I'll get the same issue.

In searching this, it seems like this may be an issue with the actuator, but thought I'd post up and get feedback to confirm or provide different insight.

 

How often do you put it in 4H/L?

 

Typically it’s at least once a month I engage 4x4

 

Try these 2 guides for help.
Really good information in them.

https://www.tacomaworld.com/threads/how-to-trouble-shoot-4x4-actuator.263525/page-7#post-8538436

 

Thanks TnShooter! I'll take some time to read through it. So far really good info. I caught that thread while searching, but didn't catch that troubleshoot guide. Thanks for pointing it out.
Just based on my quick read of the Operation, it seems like my intermittent issue is the signal not getting past the ECU, since I'm not getting the light when it happens.

 

If you need to know where the 4WD ECU is

https://www.tacomaworld.com/threads/4wd-ecu-location.495036/

 

Update:
I decided to physically check my connections two nights ago (no testing with the multimeter yet). My related mods are the illuminated 4x4 switch (Hilux switch) and the 2Lo module from @Up2NoGood.
I didn't think it was my switch since the only additional wiring I did was for the illumination portion, but I made sure everything was snug and tight anyway behind the dash.
I went to check the 4x4 ECU since I had been touching things in there with my truck ECU and completely forgot I had the 2Lo module inline with the 4x4 ECU and switch (which is obvious I know). I disconnected the 4Lo module and reconnected things back to stock. I've been engaging and disengaging since then and no issues (knock on wood).

So, I'm starting to think the intermittent issue I have is with the 2Lo module or something about it. I'm definitely not knocking it or regret buying it. I'm going to run without it for a few more days to see if I get the issue. If I determine it's the 2Lo module, I think I'll actually reinstall it and run it like that since it really only happens about 10% of the time. Uninstalling it in the field is easy enough should I get an issue.

Just thought I'd update my thread.

 

Thanks for the Update