Check for any blown fuse?
There's a fuse box in front of driver, under top of dash, just ahead of instrument panel. The fuse diagram should be a decal under that panel.
When you turn key on but not start engine, you should have a Amber wait to start light, a low air psi, and engine warning....all on a small panel right side of dash under a/c controls and above radio, as well as the strip above the left side switchs... you saying none of these come on?
My gut feeling tells me the buzzer works, perhaps the circuit is good. You may want to remove the warning light panel and check for power at the bulb socket, or blown bulbs...
1999 American Eagle
ASE med/heavy certified technician
ASE advanced diesel certified