04 Tahoe horn wiring

[fauXGT]

After a few days of searching on the old interweb, I am getting conflicting info on what the horn wiring under the dash is. I am wanting to intercept the switch signal under the dash, but am afraid of putting a tone signal from the relay back inside to find it. I don’t want to fry the BCM, or worse the wheel air bag with how some of the schematics show it with the bags. Several versions found on line, but none have the same color wires on plugs. I’ve pulled relay to test from the wheel the ground signal when I think I have the correct wire. Am setting up for switched either factory horn or FD air horn with a tap of the wheel.

Thanks in advance. Chip