4 Wheel Drive blinking indicator light

The truck I just picked up seems to have this going on. I tried putting it into 4hi while going about 45 mph, and the 4x4 light and 4lo light just flashed off and on for a few minutes. I put it back in 2hi, pulled over, turned off the truck, and the flashing lights went away.

 

Any resolution on this? Mine is doing the same thing.

 

For what’s it’s worth I was having similar issues. 4x4 high and low lights would keep blinking no matter what button I pressed or how much I drove it. Also would not go into 4x4 . So here’s what I did, I pulled the front diff actuator off I believe that’s the ADD ( what ever that stands for) took it apart ( please note where the gears are aligned when taking it alert, there’s a switch in there that needs to be hit at a certain time) and cleaned it. It was mostly clean but what I did notice is the dryed up grease. I think the grease was preventing the proper connection to the 3 prongs. I think ( and this is just me thinking ) is that the grease was preventing the 3 prongs from properly hitting their connections on the bottom. I wish I had taken pictures but if you take it apart you will notice what I’m taking about. I also spayed a little wd40 on the metal parts and played with until it all moved nicely. Put it back in and problem solved. Goes in and out of 4 wheel just like new.