I have a 99 Z71 and nothin happens when I press my tow/haul button. Any suggestions on what I should try first?

 

Same thing happened to me and I have the same truck as you do. The gear shift mechanism on the truck has a tendency to pinch the wires that run the tow/hual mode. You are going to have to pull the panel off the underside of the dash as well as the lower cover on the steering column to get to the wires. There is only one set of wires running to the tow/haul button so its impossible to miss. Its a common problem that the wires get cut. You can try to splice them back together or replace the shifter handle.

 

Ok. Thanks!!!

 

If that isn't the case you may also want to try to hit around the button with compressed air, on mine the wires were fine but wouldn't work. After fiddling and cleaning it up I finally got it to work... seems the contacts will get dirty and render it useless.

I want to say I saw someone in the suburban area suggest some sort of liquid cleaner, but my memory is a bit fuzzy to remember the details...

 

Had to fix a few that had pinched wires, my money is on that for sure