I press the button to go from 2hi to 4hi and the light stays flashing and never goes into 4wd i have to press the 2wd button then it stays on and the 4hi light goes out and all i have is 2wd . What could this be? its snowing like crazy help!!!

I have read it copuld be the acuator . how do i check it and were is it?

 

All the information you need is at your finger tips. Check the Tech Article (DIY) Index link found in my signature and look at the 4wd threads in there as a start.

And please use the edit feature to include extra information in your post if another member has replied.

 

i cant find my model i have a 4 button panel in blazer its an lt all the lights just flash when i hold them down and the only light that stays on when i press it is the 2wd light it just stays in 2hi no matter what button i push it has the awd feature it dont work either.

 

4-button == NV236. Is the service 4wd light on? Have you checked the electrical connections at the dash switch, the TCCM, and the encoder motor for corrosion and cleaned them with electrical cleaner?

 

the 4wd service light is not on and all connections are good.

do you think it could be the acuator or just a vaccum line cracked

 

did your 4x4 work before?

if it doesn't it could be the encoder motor when i first got my blazer i could push the button and it would flash but not engage 4x4. could be the vacuum actuator which is under the battery tray.

check out this article: https://blazerforum.com/forum/tech-articles-diy-29/4x4-no-worky-maybe-will-help-7180/

also i've heard of a sensor on the front differential than can be unplugged and the 4x4 will not work.

 

hey guys thanks i checked the accuator under the battery and traced the vacuum line to the T over top the distributor and the line was broken at the t i repaired it and vola!!! 4wd works perfect again..... thanks i had no idea where or how to start trouble shooting this....