Problem with my 4-wheel drive

I took my truck in to get a 3" body lift...when I got it back my "service 4-wheel drive" light was on.....I can't get my 4-wheel drive to engage now. I went back to the people that put the lift on and they disconnected the battery and checked the fuses and couldn't find the problem. Anyone have any ideas as to what it could be? I have an '03 Z71 if it makes any difference.....

Mine did this once, and it was the 4wd switch (if you have an Auto Trac transfercase) I took it to a dealer and got it replaced for $60. Haven't had anymore peoblems since.

Well im not sure if it was the lift that caused the problem or your 4WD switch. I also replaced my 4WD switch. Usually the switches go out about 25-40 k miles. Check with your dealer you might be under warranty still.