4wd Not Engaging need some help

Hello,
I have a 2001 Tacoma 4wd, 3.4, auto. Just had the oil pan replaced which required removing the front diff. Now my 4wd will not engage. Brought it back to the shop. Electrical connections and vacuum lines are plugged in at the front diff actuator and the transfer case actuator and the fuse is good. No light on the dash when the button is pushed, I can hear a clicking at the transfer case when I push the button. The shop says there is power and ground at the transfer case but nothing at the front diff actuator. Any thoughts on this? Thank you.

 

The add pushbutton 4wd are finicky. Actually the add in general. On top of that the factory Toyota ewc for the system is inaccurate for diagnosis. Buy a multi meter if you don't have one. Otherwise your only other option is to throw parts at it.

I know I've responded to at least two posts with a way to test it. But not the TC actuator, because the Toyota ewc is incorrect.

So maybe give searching the 1st gen forum a try.