97 ranger electronic 4x4 problems

i dont know why but when i startup my ranger the low / high 4x4 lights flash 4 times when i turn on the car

and now the 4x4 is not working today yesterday it would switch into high

does this mean a fuse / relay broke

does any1 know

i hooked up a code reader to the obd2 port and got PASS no codes

check wires and connector at transfer case first. could just be a broken wire or bad connection.