i have a 2001 Zr2 blazer and i went to put it into 4Lo and it just blinks the light on the switch, but doesnt stay solid, for example ill have it on 4wd auto and the light will be on i hit the 4Lo and the light will just blink and the 4wd auto light will stay on????? i dont get whats going on? it works for the other switches!

 

how fast were you going?? 4lo will only kick when your going about 2-3mph(or somehwere around there) also you can put it in neutral then press 4lo and it will work then...if it doesnt then you may have something wrong.

 

Try putting it in neutral at a stand still and hit the button. Let us know what happens.

 

On both my trucks I just come to a stop, shift the truck into N, then press the button. And I do the same to shift out of 4LO too.

 

Sometimes it helps to roll slowly, with the transmission in neutral, as you press the 4LO button.