4 Hi 4 Lo flashing after evap coil work

2014 tundra 4x4.
I’ve never had 4wd issues. I use 4wd every couple months. My mechanic just worked on my evaporator coil. So most of the dash comes out. They fixed everything, put the dash and switches back in place. They ops tested all the switches.
When they went to test the 4wd switch, the 4HI 4LO lights both started flashing and I believe the truck would not go back into 2wd (can’t remember what they said on this point…it might have stayed in some intermediate mode).
As they troubleshoot, the malfunctions are a little all over the place. The original error code was P079E. I’ve seen a lot of talk about the flashing 4wd lights, I haven’t seen it in reference to the dash getting put back together.
They’ve double checked the wires are all plugged into the back of the switches. Any other ideas? I realize they’re mechanics and am not trying to push rope here from my kitchen, but I want leverage any info this community might know so they can troubleshoot common issues.
thanks, DG

 

They obviously didn’t put it back together right. Perhaps they pinched a wire, or didn’t properly seat a connector?

 

Any other lights besides the 4H/4L flashing? Or solid, like the traction control or CEL?

 

The only other light I know for sure was the traction control. But I understand that is on due to it thinking it is in 4LO.
No other lights I know of. I took a peek at the dash, but I didn’t take a picture.

 

Transfer case stuck between positions. Check t-case wiring plug? Actuator fork stuck?

 

Flashing 4lo/4hi is now a no start, stuck starter issue?

Check out this chart to see if it can help you narrow down the issue.

 

I pulled my dash for a heater core replacement a couple months ago. Also replaced evaporator while in there, just in case. In that job, i think you have to remove the connector from the 4wd control module. It is low on the right side basically just behind the glovebox. Lots of connectors to pull on that job (>30) and easy to miss one on reassembly. Your symptoms make this a likely possibility IMHO. Mechanic can pull glove box and see the module. 5 minutes work.

 

Thx so much for all the help. They retraced their steps. Looks like a broken wire between the selector switch and the 4wd computer.
I appreciate the inputs a lot.

 

Hell yeah! Glad you got it resolved so quickly w the mechanics. Always good to hear.