i noticed on my wifes 02 trail blazer thismorning that the switch isnt lighting up in 2hi allwheel 4hi and 4low, when i shift it it dosnt shift either,i checked the fuse its not it, has anyone had this problem before

 

This just happened to my '02 as well. Did you find a fix for it?

 

tblazers are notorious for having bad 4X4 switches. But there are also other causes for this concern such at a bad Transfer Case Module, where the TCC Module doesn't waske up when the key is on. Re+Re-ing the fuse will cause it to wake up, but it will happen again and will need a new module. There is also a harness attached to the side of the underhood fuse box that could have a backed-out or damaged pin. Cause for this is usually an improperly routed harness. It is usually routed too tightl.This is a 38 pin connector.

 

I have had the same problem like 2 or 3 times in owning my 04' the past year... my advice... don't bother with it. I shut off the engine for a bit, the computer resets.. and then its working again. Good news since you have 2 wheel HI it will automatically lock into that... for those unlucky ones that have it in 4wh AUTO all the time... that is automatically what it reverts into, therefore ur in 4wh when ur switch dies...