1998 4x4 not working right
 

i just got the car 2 months ago. the 4x4 has worked great no problems at all. its the 3 button. today i went the store and came back home and i have to put it in four wheel drive to get through the alley and nothing happened. no light flashed or nothing. just the 2 wheel light is on. i tried everything and the only way i can get it into 4x4 is put it in neutral and hit 4Lo. if you hit 4Hi the lights just flash and it stays in 2 wheel. while in park if you hit any button it does nothing. it also jerks pretty hard to when it goes in 4Lo. any help would be appreciated.

You need to run the codes:
OBD2 Non-Automatic Transfer Case Diagnostics

Also worth checking out:
4x4 No Worky.... Maybe this will help....

ok i ran the codes. all the lights are flashing 2 times so that must mean code 2. im new to working on these blazers so from what i read i take it this might work. since it takes 25 bad times of the tranfer case shifting to throw a code and not work, if you unhook the battery for a half hour it should reset it and work right. if not i need a new encoder motor. correct me if im wrong and give me any other advice please. thanks ryan

Yeah, try disconnecting the battery. That might buy you some time, but you likely need a new encoder motor. It will probably fail the next time you really need it.

To make sure, check the usual things like electrical connections at the TCCM and at the encoder motor for corrosion.

i undid the battery for a while and hooked it back up. everything seems to be working. i engaged and dissengaged it a couple times and it all works so ill see how long it lasts.

I have the same exact problem with my 4x4. I will try unhooking the battery tomorrow and see if that works but could that cause damage to the 4x4 if its engaging but the encoder motor is bad?

i have the same exact problem i can unhook my battery for like a minute( i think that's all it takes) i can switch back and forth a few times then it just stops like the person above was saying, so what do i need to look into to get this solved?

What you are experiencing is an encoder fault. The TCCM will attempt shifts a few times even when a fault is present. During those attempts, it will shift, but as the TCCM encounters the faults, it records them. Once it gets to a certain count, it will lock out the shifts and store a code. Checking for codes is explained for both the NV236 (4-button) and NV233 (3-button) setups in the Tech Article (DIY) section.

I have a 96 with the NV233 t-case (3 button). I am having similar issues as the other guys in this thread. With the exception that my four wheel drive works intermittently. Also sometimes when I start it, I have no light on at all to indicate whether it is in 2HI or 4HI. Usually after a while 2HI will light up. I have pulled the codes which is code 2. If I have read everything correctly, that would mean that I need an encoder motor. Does the 2HI light not coming on all the time mean that I have other problems?
It will go into 4LO, but not 4HI. When it goes into 4LO, sometimes both HI & LO are lit up, sometimes not. The dash switch is new. Actuator is pulling the cable and locking the front axle. Should I check anything else before I get an encoder?

You have covered your bases. Sounds like new encoder time.