Depending on your model you either push a button on the dashboard or shift a lever on the floor. Since Chevy also made two wheel drive models you many not have a four wheel drive option. You should be able to shift at any speed, but I've always found it best to engage the 4wdr system at slow speeds on level ground and when the engine isn't under strain.
I hope that helps.
A 1996 Chevy Blazer Does have a transfer case IF it is equipped with 4 wheel drive
where is the transmission control system on a 1996 chevy silverado 2 wheel drive 5.7
Front-wheel drive.
5 on 4.75
200 cc
nothing
no all front wheel drive the best of my knowledge no all front wheel drive
Underneath, drivers side, inside frame rail, aprox under drivers seat.
1996 Chevy blazer timing chain
my Chevy blazer power seat on my 1996 Chevy blazer isn't working
what is the distributor setting for a 1996 Chevy blazer
Check the fuses