2002 toyota tacoma 4x4 problems
 

I have a 2002 tacoma that won't go into 4WD. I have taken it to 3 different mechanics and have been given 3 different solutions? Mechanic #1 says transfer case actuator is bad. Mechanic #2(toyota dealer) says ECM is bad. Mechanic #3 says front differential actuator is the problem. Not sure how mechanics 1and 2 came to their conclusion, but toyota dealer told me there was no power out of ECM to actuators? Mechanic 3 said they have power to both actuators. When they unplug power on front actuator, transfer case will go into 4WD...also get indicator light on the dash. When they plug front actuator back in, 4wd goes away. I tend to trust Mechanic #3,but still not sure which way to go? Any ideas out there?