I have a 1999 Suburban I can lock and unlock the doors with the remote but the lock button does nothing.

 

Welcome to the forum!

I'll venture a guess that the switch in your lock button is bad. You can test it with a multimeter. Does it work on the passenger side?

 

No all windows work but none of the lock buttons. I thought it was a relay because the locks and the power seat share the same relays, and the power seat all works but the forward and back button. Both relays check out as good.