The blinking light on the dash means that the lock switch sensor on the elocker motor at the diff is not getting a closed loop signal. In other words, the elocker actuator is sending a signal that it is trying to lock, but not able to lock locking. (Sort of....really it means the lock ecu is not receiving a lock signal from the lock sensor switch on the elocker motor.) As mentioned above, this could be caused by the central diff located in the tcase not being locked (btw if you don't have a "center diff lock" specific switch, you must put the tcase in LOW in order to lock the center) but could also be caused by a handful of other things... A few of those common reasons are that the lock teeth are not lining up correctly; another is that the lock fork is seized; another is that the harness connecting the lock actuator end of the wiring to the body wiring is corroded or gummed up with junk. When you are trying to lock the rear, are you driving? Are you in LOW (or have the center diff locked)? If driving, are you on dirt or pavement?--make sure you're on dirt if you're driving. If you're not driving, you will not have much luck getting the rear to lock unless you jack up one tire off the ground and spin it with your hands. Do you hear any clicks or winding type noises from the actuator? EDIT: Jut reread your post more closely. With no power out of ecu to the actuator, I think WarDamnEagle is prob on the right track with the center diff. -Ferg