My Blazer 1997 will engage 4x4 hi but not 4x4 lo. When i start the car all buttons lights up and then 2wd, stays on. And there is no problem to engage 4x4hi and it works normal when drivning. But when i press 4x4lo button notting happens, It dosen't flash or anything.For the record, when shifting to lo gear i have had the gear in neutral.

 

Have you checked your vacuum lines? Maybe a loose/bad connection.

 

Just to be sure, when you say 4Hi works, are you able to tell that 4wd is engaged by trying to turn in a tight circle on pavement and feeling/hearing the front tires skipping and binding? I ask as I think it may be possible for the 4Hi button's light to be on but with the transfer case not to be engaged with only the front axle being engaged.

No matter what, you also could be having trouble with your transfer case control module (TCCM). Apparently, sometimes the failure mode is that that electrical connections to the TCCM become dirty./corroded. The TCCM is easily accessible under the passenger side kick-panel. Look for threads/posts on the TCCM.

 

I have tested the 4x4 in a slope and I feel that it works.

 

If so, then I would suggest checking the TCCM to see if it is working properly to direct the transfer case to switch to the lower gearing.

 

Assuming you have a 3-button NV233 transfer case and all seems normal except nothing happens when you push 4Lo...... Start by checking for 4-lo engage signal at TCCM behind passenger side kick panel. See post#3 here
https://blazerforum.com/forum/2nd-ge...-blazer-89670/

 

Yes, I have the 3 button one. I will check my TCCM. Thank you guyes for your help. I´ll keep you posted.