RR Diff not working. Light on dash keeps blinking.

I have a 2006 Tacoma Prerunner with the off-road package. I'm taking it into the mountains in a couple weeks and wanted to test the RR Diff to ensure it was in working order. When I press the button I hear a clicking noise near the rear wheels so I think it's locking but the light on the dash keeps blinking without stopping. The manual states that the light will stop blinking and stay on when the diff is set. Any ideas on what I should check or do to fix this problem? Thanks!

 

The locker has to line up just right before it can lock together. It does this by the two rear tires spinning at different speeds. Turn all the way left or right and drive in a circle. It should lock before you make it too far around that circle.

That may sound crazy, haha but Toyota designed the locker to be used only when stuck (so the manual says). If you are stuck one tire will be spinning so it will line itself up while stuck.