My 1997 S10 Blazer LS 4wd 2dr 5-speed manual does not go into 4wd-low. When I push the 4wd-low button it engages the 4wd-high and the low button just flashes. Any ideas???

 

Vacuum switch on the transfer case, front axle actuator under the battery tray, broken actuator cable, bad axle clutch, bad switch on the front axle, encoder motor, TCCM, wiring. Could be any one or more of them

Start by checking for vacuum at the axle actuator when 4WD HI is selected, engine at idle, trans in neutral. Post your results.