Hi,

I have a 1997 Chevy Blazer 4x4 and the 4WD doesn't work anymore. When I press either the 4hi or 4lo button it blinks a few times and nothing happens. I have been told that trying to repair this may be a black hole in which money never returns. Is there any inexpensive way to diagnose the problem? Apparently swaping out the switch in the dash may be a place to start.

Any help being pointed in the right direction would be great.

 

Check your fuses. There's one for the 4WD...I had a blown fuse and it did the same thing. Once the fuse was replaced, the motor on the transfer case made noise and it switched properly.

...just the other day I went to switch back out of 4WD and it blew again. Ran over to walmart, got another 15 fuses and it switched fine after replacing the first blown one. I have 14 left in the console...

 

Check the fuse as suggested...when you press the button can you hear the encoder motor trying to engage?
My guess is it is the encoder motor..they're terrible for going..but if you hear it trying to engage it might be something else.
Mine got diagnosed as a bad encoder motor, but it turns out the terminals in the computer and the encoder motor itself corroded to hell. We're just replacing the terminals..waiting for the parts to come in.

 

Lets start with some information about your truck... Do you have a 3-button switch or the 4-button w/ Auto4wd switch?

If you have the 3-button switch, run a search for NP233 or NV233. There are two good articles in the Tech Article (DIY) section. Have a look at the thread stickied at the top of that section for the summary of all threads in that section.

 

honestly don't know a whole lot about blazers, just got mine about a year ago, but i had the exact same problem on my 2001. Ended up being the 4x4 vacum selenoid. A mechanic changed it and it cost me like 180 i think for parts and labor works like a champ now. But i wouldnt take this route till u have too seeing as how you gotta pull a few parts just to get to it.

 

Check the vacuum hose on the firewall, DIRECTLY above the distributor. Mine kept breaking off, mainly due to the shorter it got, the more tension was on it. I finally got a coupler, and extended it, last week. $3 fix!

 

Thanks for all the replies. I will check everything you have suggested and get back!

 

Well I guess the simplest solution is the first one you check first! It was the 20A fuse for the 4 wheel drive. It goes to show that don't always believe everything you mechanic tells you. There was about $800 in suspension work that was fixed and he said that the 4WD was a preverbial black hole for money and would be about $1500 to start. And all it took was $0.15 fuse!

Thanks for all you advice!

 

The most unspoken first trouble shooting step is to check the fuses. I suppose it should be said more often.

Glad you got it figured out!