Hello everyone. Glad to be here. I have a 98 blazer, and am having trouble with the 4x4 working. I have done some checking in the search and got some good leads. Last year I noticed when you try to get it in 4 hi, all it would do is blink, so I did the unhook the battery deal, and all was good. I was driving around in 4 hi the other day and it worked great. Well now it wont go into 4 x4 it would blink and I would hear the click from the tccm once in a while, But it wont always blink or click(tccm) for the most part now, it wont blink or click. But if I put it in neutral and go to 4 lo I can tell it goes to 4 lo but the light will not show it?? Im thinking its the tccm or the 4 wheel drive switch itself?? Any ideas?? Thanx in advance Also removed the lsp courtesy fuse for half hour turned the key on and off 5 times started it up. still the same outcome

 

Since you didn't mention Auto4wd or how many buttons you have on the switch, I am going to assume you have the NV233 (3-button) transfer case.

Check this out:
NV233 No Mode Switch (ie. 2HI to 4HI)

Another notable thread on diagnosing NV233 problems:
NV233 transfer case / encoding motor switch

Both threads are listed in the Tech Article (DIY) Index link in my signature. This summary/index thread is also stickied in the Tech Article (DIY) section.

 

Thanks! good info. Yes it is the 3 button, went to the wrecking yard today and got a tccm for 57$ and is now working great!! and good timing it's snowing like a some b*#ch up here in Spokane WA