4 wheel drive light flashing

Thanks for the hint about this thread TnShooter!
https://www.tacomaworld.com/threads/4wd-system-operation-help-thread.742420/

it seem I got no good value with voltmeter on pin TL1, TL2, TL3, 4WD, L4, DL1, DL2, ADD.

Where to go first?
I put the picture of my voltmeter reading in case someone would know what could be wrong looking at those numbers.

 

Since all your ADD voltages (Dl1, DL2, & ADD) are 0v I'd start with unplugging the ADD on the front axle and make sure they all go to 12v, if they do then your problem is in the ADD actuator.

 

Looks like TL2 limit is not closing on the transfer case.

 

It's not allowing any shifts because all the limits on the ADD are at 0v which is out of range.

 

Yeah maybe a short or bad ground on that sub harness.

 

If the ground was bad they would all be at 12v or so, since they are all 0v there's ether a short in the ADD or wiring. That's why I said to unplug the ADD and make sure they all go to 12v, if they do it's in the ADD if they don't it's in the wiring.

 

My first thing to do would be unplug at the ADD connector as suggested and check for 12v at the connector. You can go a step further and measure each limit switch to the coming ground on the ADD if you think that helps but the way the system grounds the limit switches it’s not really possible for two to be closed at the same time.