This will help you determine if the problem is with a defective locker actuator inside the axle housing or the Final Drive Control Module (FDCM) AKA the SmartBar/front sway bar that controls the lockers. You can also unplug the FDCM and check for corrosion on the pins. I've seen moisture get inside on the circuitboard and cause all kinds of problems, including random locking when the switch is in the "Unlock" position or failure to lock with flashing indicator lights. Corrosion on the pins is your first indicator that there's moisture inside the SmartBar.
Also remember to check your sensor magnet that mount right next to the locker actuator. They can get loaded with fine metal particles that changes the air gap between the magnet and the sensor, which can cause flashing indicator lights and failure to lock.
If you determine that the axle actuators are good and that your problem is with the FDCM, my "Full SmartBar Bypass" will restore the proper function of your lockers and sway bar disconnect. It replaces all the electronics, except for the locker actuators inside each axle housing and the factory dash switch. My module mounts under the dash, so it's not exposed to all the harsh elements like the FDCM is. It retains the full function of the factory dash switch and works in any transfer case range.
Email me your mailing address and I'll send the test harness ASAP.
AbelComponents@yahoo.com
