Hello, I have a 1999 ranger 3.0 automatic. I went to drive it today and the 4hi & 4lo lights are flashing every so often. The last time I drove it it was fine and the 4x4 worked perfectly. Today with it flashing I checked the vacuum lines on the front end and didn’t find anything wrong. I did move the dash switch from 2wd to 4hi and nothing happened or changed, there was not any “clicking” sound either. Would anyone have any ideas on what and how to check out components or other vacuum lines? As far as I know the dash switch and all other parts are original. Truck has 206,000 and I’ve owned it for 11 years (had 150,000 miles when I bought it) . Thanks for any advice

 

I've read that flashing 4WD lights mean the 4X4CM is working but that something else is broken.
Maybe the shift motor isn't working? Has yours been worked regularly?