I have only owned a Blazer (1997) for a short time. mine just started acting up once we hit - 10 degrees F. from my understanding it is not uncommon that the Solenoid just sticks. you can hear mine click but as I go it partially engages and then slips back out. not sure yet if it is the front end or the TC but my bet is on the TC since my 1984 s10 had no problems with the front end and I was a lot harder on that truck. I will play with it once the tem gets a little above 0d F, yuck

 

These flashing light issues are typically caused by encoder faults or a fault between the TCCM and the encoder causing the TCCM to revert back to the previously chosen mode. First check to make sure that the connection to the TCCM and to the encoder motor on the side of the transfer case are clean and corrosion free. If that checks out, then you may need to dig a bit deeper into the system.

For those with the NV233 transfer case (3-button dash switch), there are some pretty good threads in the Tech Article (DIY) section.

For those with the NV236 transfer case (4-button dash switch), you need a scan tool capable of accessing the TCCM to read the codes present for some direction.

 

well I tore into mine over the weekend and found a problem. if you are not getting the front end to engage, a quick trick,, manually override the vaccume and pull on the cable, if it will not go in manually it is possible that the teeth on the axle have been mushroomed from wear. to get to this you will need to pop the upper ball joint on the passenger side. pop the inner side of the CV axle out and then remove the housing from where the CV axle enters to where the gears are for the 4x4. I just used a small air sander to clean them up and mine works now. My light was not flashing but I believe that this is because the switch is stuck in the closed position. if you need more details let me know.. thanks all

 

JUst a quick note to let you guys know mine is fixed. It wasn't the TCCM it was some vacuum hose with a plunger type thingy that was broke. sorry for the laymans or laywomans terms...don't have the bill in front of me to tell what it is actually called. $200.00 part. Totally worth it to me. Thanks guys

 

A rusty cable caused my 4x4 not to work properly , and intermitantly try penetrating oil on it

 

There is a Front Axle Actuator Valve on the firewall almost directly above the distributor. My 4x4 buttons flashed and never engaged. I replaced it this valve and it has worked perfectly ever since. (P/N 15165891) I had to go to the dealer for it and it was the best $50 I have spent so far. . . .

 

my 4x4 stops working to, the lights just blink, there is a vaccuum hose under the battery that was sucking air, put it back on and now it works great, if you have 4 low and lights are blinking..and no 4 high.........you should check this hose, simple fix