hey my name is Tj. I am new to this site.I drive a 99 Chevy Blazer LS and the 4 wheel is broken. well i bought the vehical last spring and we tested the 4 wheel and it worked. all of a sudden this winter i try to use it and it wont kick in. the lights on the dash just flash when you push them, all besides 2-hi. ive checked the fuses and have crawled under it to check but i cant tell. i have a system in my blazer which may have caused wires and such to come lose or would it be a different problem? just want to see your feedback. thanks

 

The news is most likely expensive, even if you do it yourself. My 98 LT went into 4wd without problems and then one day I put it in 4 on uphill wet grass. Clunking from the right, front axle. I bought an extended warranty ( thinking something like this would happen). 2 weeks later and $1200, I got it back. They first found a collar wouldn't engage the right front axle shaft which caused the quad pack in the differential to break. News gears (inexpensive parts). Put together then the TCCU (transfer case control unit - right front kick panel) wouldn't communicate with service computer and wouldn't engage the transfer case (couple hundred bucks for part - need tech computer to program). Changed that and would shift into 4 but would kick back to 2 on it's own. The actuator worked fine through all this. Then they found the transfer case encoder motor would not engage the transfer case. I learned the left front axle is always spinning, but not engaged with the front diff until in 4. A sleeve collar slides inside the axle to "lock" the right front and differential to complete the 4 engagment process. Good luck. If it's the actuator, that's under the battery and about $160.

 

alright thanks for your help ill check it out...anyone else?

 

start simple (and cheap) pull the battery and follow the vac lines from your actuator (inspect the actuator diaphragm too) vacuum issues are the most common cause of non functioning 4wd in these trucks. If this is not your problem what did you waste a few minutes of time?

 

alright i havent tryed that but i went out and looked at it a little bit. when i push the button for 4 low it makes a clunking noise as if it is going into 4 wheel but tires dont kick in and the buttons still flash besides 2 hi. thanks for your help and keep them coming! im not wanting to spend a bunch of money seems im just a college student lol.

 

Have a look around a bit. There are numerous questions and answers on the 4wd problems these vehicles go through.

As far as the response from Chief, that is a very rare chance that there will actually be that extensive of an amount of damage. And the actuator under the battery is hardly $160 unless you like paying inflated charges to about 3 different middle men in the parts procurement process.

As far as giving you any ideas on how to fix your problem, you need to supply us with some more details about your truck. Specifically, what 4wd system do you have? 3-button NV233 or the 4-button NV236 with Auto4wd?

 

oh sorry ive got the 4 buttons the one with the auto 4wd....which also just blinks like the rest of them

 

The NV236 brings some considerable complexity into the equation. Have a look at THIS POST for a good discussion and links to some related material.

 

I just posted this on another question about 4WD. My 2003 stopped shifting back and forth between 2WD & 4 Hi (lights flashed and I could hear the switching noise, but it wouldn't make the switch). I could get into 4 Lo when in Neutral, but nothing when I tried 4 Hi whether in nuetral or moving. Turns out my battery was dying or too low. Voltage looked fine on the dash gage and the connections were clean, but the sudden cold weather and lack of use for 1 1/2 days made the car slow to start, even after running it for a while. I read somewhere this might cause it, so I bought a new battery and it solved my problem.

 

I rember on my 89 s10 I couldnt get it into 4 wheel and it was a vacum problem, I would start there. You could also try putting it in nutral when shifting into and out of 4 wheel, I always do.