Need Help with faulty 4x4 diagnosing

So, I'm finally getting ready to turn my taco over back to daily driving duties. I figured today, i should flip the 4x4 switch to make sure it works. Guess what? It didnt. I found a lot of threads where people will replace the actuator motor and i found lots of diy's for that, but i couldnt find a good thread with some good diagnosing steps to follow before i go ahead and start swapping parts. How do i go about pin pointing what the problem is? I don't really want to spend $400 on an actuator motor if its my switch that is bad.

Here are the symptoms - first off, its a 2006 taco DCSB. Has just under 138K on it. When i flip the 4x4 switch, absolutely nothing happens. No sound of the motor trying to engage, no lights on the dash board, nada. I read on other threads that sometimes it will just blink on the dash, and i believe that was part of the actuator replacement thread, but i'm getting zero lights. Fingers crossed its the switch....

 

You can test all inputs at the 4wd ECU very easily with a multimeter and some backprobes.
I would start with checking power and ground at the 4wd ECU, if that's good then check the 2 input signals from the select switch.
https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/

 

Before you start throwing money at it take it out on a dirt/gravel road and go for a LOOONG drive in 4X4. Switch between 4X4 and 4X2 some as you go. If it hasn't been used in a long time it might just need some use to get everything warmed up and lubricated.

 

This is great, i will start reading through this!

True, i may as well give that a shot too. I use my integra for daily duties in good weather and the truck in the winter mainly. I've put maybe 800 miles on the truck since April, so it probably could use a little exercise.

 

So, i had high hopes that maybe just running it in 4wd for a while would do something. I drove about 10 miles on some backroads with the 4H engaged and nothing happened. Later on today, i tried to engage it again. It came on right away and i could hear the front locking in 4wd. i drove like this for about 6 miles just to make sure everything was working. I disengaged 4wd when i got home so i could back into my driveway. I attempted to engage it again, this time nadda. So, i ordered some back probe tools off Amazon and i'll start to poke a little further next weekend hopefully. I can't imagine i have too much "good" weather left to drive around my Acura.

 

Honestly, that sounds normal, given how little you drive it. I'd advise doing some more dirt road attempts, as suggested above. Mine was acting like that a few weeks ago, because I only used 4hi once all summer, but now with the snow I have to use it daily to get out of my driveway.

 

OP said he gets no lights at all, if the actuators were physically stuck the 4wd light should still flash.

 

I normally get the initial hesitation from the first 4wd engagement, or when it gets used infrequently, but it never last more than maybe 10 seconds. So i think this is most likely something different than just not enough use.

 

Well, my diagnosing was pretty simple. I'll keep monitoring it to make sure the issue is what I think it is. So, when you put the switch into 4HI, nothing happens. But, if you put it in 4Hi and very slightly move it to the left, 4wd engages in a matter of 2-3 seconds. So its something with a contact in my switch I'm thinking.