My 1998 s10 zr2 blazer wont engage into 4wd. The light flashes and you can hear the t case module click when the light flashes, it does this about 5 times and wont engage then the light just goes back to 2wd. Does anyone have any advice that can help me?!!

 

I have the same year and model, and had same problem. It turned out that it was a bad vacuum hose that was preventing the 4wd from engaging.

My 4wd will now engage but from time to time it will slip out of 4H, along with some nasty grinding noises. No problems with 4L though, so if I get stuck I can at least get out.

Anyone have any ideas as to why my truck would slip out of 4H? It seems to happen when I decelerate or come to a stop.