Two separate circuits with two separate fuses and two separate problems. Assuming the dome light bulb is good, the dome light has a switch which allows you to put it in three different modes, on all the time, on only when a door is open and off all the time. Be sure the switch is not in the "off all the time" mode.
Assuming the fuse for the horn is okay, the horn problem could be the switch contacts in the steering wheel are dirty, a faulty horn relay or a bad horn. It will take a little detective work to find the cause.
Have you checked your fuses?
Horn relay Switches at steering wheel
Have you checked your fuses? Does the turn signal light up at all? If it does, you most likely need to replace a flasher.
have the clock spring checked turn steering while pushing horn
I hope you checked the fuses first.
The next thing to check on a 2004 Yukon when there is a bad horn is the wiring. Looking for any burned or frayed wires that connect to the horn.
My wrx 1995 stopped working because of the carbon brush on the rear of the wheel. fitted after market neon horn swith to dash to get round it.
check your fuse box. your horn, dome light, and cig lighter run off the same fuse
All my fuses and relays work. My horn and cruise control do not work. Also my airbag light is flashing. Could it be the clock spring and if so How do I change it out.
Check the flat cable coil in steering wheel, it may have broken leeds.
WIRINGS!!
Checked the fuses, if none are blown then the switch in the steering wheel probably went bad and needs to be replaced.