I have a 4wd 1997 blazer with a push button system (3buttons, 2hi, 4hi, 4lo) and i am having trouble with something with the 4wd sysytem.

I try to engage my 4wd and it wont engage, i hit the buttons it does a single click and then nothing no matter what option i hit, and none of the light come on, 4hi,4lo only come on for a sec when i start the truck but 2hi never lights up!

any advice or suggestions?

 

Not sure what it is but I had the same problem with my '97 when I had it I know its an electrical problem but be careful mine work work sometimes then stop working ... but when it stopped working it would randomly switch into 4HI and well doing 80 down the interstate in 4HI cost me the Drivers side shaft ...

 

thanks man,

i wonder what causes this to do that? should i replace the switch you think to try and correct it?

 

I know its not the Push button Switch I tried replacing mine .. made no difference ... could be with the Solenoid or the relay Never got to Diag it personally.

 

Mine had a similar problem (2002 model). Long story short, the front differential was about 40 percent low on gear lube (takes 80/90 gear oil). I filled it up, now it works absolutely fine. Been a few weeks now and still working stronge. You may have a mechanical engagement issue is it's low on fluid. Hope this helps

 

This problem sounds like it is electrical in the switch. The switch is fairly simple on the NP233 transfer cases.

Have a look at this:
NV233 transfer case / encoding motor switch

And also have a read through this:
OBD2 Non-Automatic Transfer Case Diagnostics

 

My experience with this same scenario was the Vacuum actuator.

The light is triggered when that actuator ( under the battery tray) cannot pull in the cable to the front Diff enough to trip the switch for the 4WD light.

OK.. here's how it goes. You push the 4WD button (either high or low) that sends power to a motor on the transfer case, when that motor turns to engage the Transfer case it also opens a vacuum switch. the vaccum hose runs to this actuator under the battery tray which causes a cable to pull in. that cable runs to the front Diff( passenger side) This actuator is known for getting a tear in the rubber so it cannot pull in as far as it should. so the cable cannot engage the 4WD and trigger the Dashboard 4WD light.

climbe under the fron of the car, pull back the rubber boot at the Diff and WITH THE CABLE still going into the Housing,
loosen that 5/8ths? nut off the cable. with that nut all the way loose, pull on the cable and see if the dash light comes on. Or you could take the battery tray out and look for a tear in the rubber actuator.

 

Is it possible that the 4x4 can just freeze up in the winter and stop working? I had to use my all-mighty '93 Blazer to pull some friends out of the ditch last week in the middle of a blizzard and now the 4HI light stays on and I can't turn it off or switch it to 4LO.

Now that I read that last post about vacuum actuators it's making me worry that this isn't just a simple problem anymore.

Also now that the 4HI is stuck on i can hear a fast clicking nose coming from the driver's side of the truck by the front axle when the truck is running.

If anyone has any ideas about this problem any advice would be appreciated.

 

If it is clicking at the front axle, then your cable is stuck, partially engaging the locking collar. I would lubricate and work the cable until it moves more smoothly.

 

Thanks so much. I will give that a try ASAP and let you know if it worked.

Also, I forgot to mention that I have the electronic 4x4 so I dunno if that affects your solution or not. And if not, well, umm... I don't really know how to find that cable you mentioned so if you could offer me some more of your god-like wisdom it'd be uber-appreciated.