No 4WD 2003 silverado Ex cab LT

[Ralphw62]

Hi,
Im driving a 2003 Silverado ex cab LT

Last night we had out first sloppy weather of the season here on Long Island. The switch seems a little erratic and sometimes it works fast or slow and other times I can hear it shift into gear and others not, No warning or Check engine light, I'm not even sure if there should be one. I found the only fuse and its good. I used my scanner on it and no codes. its the first time I ever had a 4wd issue all my years with Chevy trucks. I will have a new switch here tomorrow, was a good deal. I hope its the problem but I have my doubts. I was having electrical issues a couple months ago and hope its not that again. any Ideas? also what's a good way I can be 100 % sure its out? hard to tell it was so slippery and cant see tires while driving.



I did have an issue with a U Joint/ Had one going bad. about a month ago. The guy replaced it and the next day the whole drive shaft dropped from the rear. I was able to move the truck by putting it in 4wd I was 2 blocks from shop and I got it there that way. I sure hope that didn't mess it up.
Thanks!!!!
Ralph