Toyota Repair: 4Runner 4 wheel drive not working, rear differential, front wheel drive

Question
hi Ted, my 92 4Runner Metro (4cylinder, automatic) is displaying the 4WD light on dash, but the front wheels are not engaging. The back wheels will spin out and the front do nothing.
Also, recently had it in shop getting work on the rear differential. When I got the 4Runner back the rear anti-lock brake light was on in the dash, when it hadn't been before. Now a few months later it comes on periodically. any ideas?

Thank You
Debi

Answer
The front differential to provide front wheel drive is operated by a vacuum controlled actuator, it's located on the front differential housing, these actuators can cause this condition so have it checked out for this.
The ABS warning light is probably caused by a malfunctioning ABS speed sensor which is located on top of the differential housing.