last night, I was driving my 2000 s10 on snowy roads, so I put it in 4HI, well, got in this morning, NONE of the 4WD indicator lights are on, and seems to still be in 4WD.. I have tried putting it in neutral, pushing any of the buttons does nothing.. no bad fuses.. any suggestions, and ideas at what Im looking at? have you heard of this?

 

My 2001 S-10 crew had a similar problem a couple of weeks ago. The indicator showed it was in 2WD, but the transfer case "whined". Brought it to the dealer for a check. Of course it was fine on the way to the shop. The put it on the lift and confirmed that it was in 2WD.

We had more slippery roads yesterday. Selected 4HI and nothing happened. You could hear a "thunk", but no front traction. Brought it in today and they had to replace a vacuum switch. Seems okay now. First problem after 78000 miles.

 

You'll probably have to replace the whole 4-whell drive switch pannel. The thing is a piece of crap. Cheaply made. I've had to replace mine twice and yet again I have to because it wont go into 4lo...not really in a hurry though because 4hi still works.

 

your actuator is vacuum operated so just make sure the vacuum lines are all in good shape and there are no leaks...and probably check the switch too it may have loose connections or as GSXJuggalo said...replace itthey're like $10 at O'Reilly Auto Parts.

 

where exactly are the vaccuum lines ran?