No 4wd

[GasGuzzler]

i have no 4wd the lights ain't on an it says to service 4wd? it is on a 04 chevy silverado 1500 z71

New problem

Make sure the switch is plugged in.

Make sure the fuses in all three locations are good. Make sure the module is plugged in and you do not have a windshield leak getting the module wet.

Beyond that you need scanned for codes.

You also need to make an introduction topic in the newbie section.