When running air condition, if i blow the horn both stop working, until i replace the horn fuse

Why fuses blow or how to find short circuits or drains !

fixkick.com/power-elect/blows-fuse.html

(the Park (tail-running) lamps go to up to 20+ places) ... The below covers shorts in the cab box, not the 50-100 amp engine bay fuse box that loves to rust out.

Could be a wiring problem or the clockspring in the steering column.
You would need to pull the steering wheel and test the circuits.

its shorted, that line, the fuse blew saving you a nice fire.
are you using the correct fuel shown in you operators guide, see index , fuses.

do not mess under dash until you defeat those air bags, they can kill you. (break a neck easy) the schmatic is here.

official FSM
https://suzukipitstopplus.com/Products/1066-2006-forenza-reno-service-manual.aspx
$4 cost, dirt cheap.

first look at the actual horn, see damage there, it or the plug.
pull its plug and safe off (means tape it) and see if fuse blows yet?
always work the simple side first, not air bag side,or the
air bag clock spring, inside, steering last.

its either path A shorted, (most likely but fate wins)
or Path B, shorted relay coil.
if horn unplugged, fixes blowing fuse, the horn is bad.
easy huh?

damaged wire maybe.
Locate the horn that blows and follow the wire back until you see the damaged area.

Should only be one power wire running to the horn.
Very strange that the fuse/relay didn't stop it from happening.

let me know what you find.

Check for a blowin fuse

Sounds like the horn itself is shorted out. You didn't mention if the blown fuses were a result of using the horn. A horn in construction is an electromagnet acting on a diaphram; if the electromagnet develops a short, it causes an overcurrent condition and will blow the fuse.

I have or should say had same issue on 1996 cirrus quick fix just remove the HORN RELAY located on the left side of dash relay only controls horn. To really solve the issue at hand you must replace the clock spring on the steering wheel dis-arm air bag before messing with steering wheel to avoid activation of air bag disconnect battery for 10 min then its safe to fiddle with steering wheel safely.
Chino S.G.V

Check blower motor fuse. If blown replace. Be aware. If fuse again blows or you find fuse to be in good condition it indicates a problem in blower circut/components. Do NOT replace with larger fuse to cover problem it will cause further damage. $$$
good luck

Replace your steering column clock spring which carries the signal from the air bag, horn switch, and criuse controls.

The horn wire is grounding out inside the column. Probably got pinched or a little insulation stripped. You will have to trace the wire thru the column or just replace it.