i have a 2000 blazer zr2, 55,000 miles and have been having problems with the 4x4. when i first got it a few weeks back the 4x4 dash lights quit working the 4 button selector. i tryed unpluging the battery fuse ect, finally just crawled under and wiggled the two pluges, now my lights work and service 4x4 light went off.

Soo first snow fall this week and no 4x4, when i press the buttons they take a second and then stay lit like they should, i can my hear case transfer, but no 4x4, ive tryed driving it in the 4 selection anyways hopping maybe it would go in, no luck, if anybodys got some cheap suggestions to try first before i dump any more money into this truck let me know please and thanks.

my mother has a 2004 blazer 4 door same problem, 3 button selector, i can hear it transfer but no front tire action, 4lo is the same thing, just the torque changes no 4x4, it would be nice to fix them both with winter comming, also i wont be stuck pulling my old lady outa the ditch

 

I dont know a hole lot about the blazer/jimmys yet.. but someone correct me if Im wrong.... Check the vacuum line that goes under the battery tray i know my 96 has that atleast. Or you actuator which is under the battery tray could be bad.

 

x2 on that line, seems like a when problem not an if.

 

If wiggling the harness/connections worked for a short time, then the problem is likely with those connections. Corrosion is a somewhat common problem on these trucks. Typically it is the connection at the TCCM that likes to corrode.

On the '04, that sounds more like a vacuum problem as ir2005 stated. Check out the '4wd no worky' thread linked to in the Tech Article (DIY) Index link in my signature below.

 

well i looked under the batter tray and my plunger pulls properly so i know that my vaccume is working correctly, whats next that would have to do with my frond end engaging?

 

did you try pulling the cable by hand? try that and see if you have 4x4.

 

yes i pulled it by hand to see if it pulled any more, and the plunger pulls it as far as it goes, still no front wheel drive,

 

I had the same problem and after changing $150 worth of parts I checked the 3 line vacuum switch on top of the transfer case, tube wasn't fully on so I removed the vac/lines, switch and then I took door lock deicer anti-freeze with lube spray (wear rubber gloves its hard on the hands) and spayed it into each of the three ports and worked the ball, press the ball in hold and spray to clear each port (watch your eyes) reinstall with fresh Teflon tape put the 3 line adapter back on I believe there is a line on the tube adapter that lines up with a line on the switch TAKE NOTE BEFORE You remove cause you want it somewhat in the same situ. Hope this works for ya.