1997 s10 blazer 4 wheel problem

I have an s10 blazer and a few months ago the 4 wheel high light was on and lit wasnt in 4 wheel drive then a few days ago for no reason at all it shifted into 4 wheel low and wont come out but the high indicator light is still on can someone please help me

Look in the "How To/Tech " section for 4wd info.
By going thru the possible causes (vac lines, sensors, switches, actuators, encoder motor, 4wd PC called the TCCM, you will find the reason and fix it.