Horh does not work.the fuse (10amper) is o.k

main fuse

That's a lot of questions
I think your best to leave the answers to
a repair shop, if don't have factory manuals
for reference, as to how the system works or experience
with vehicles

Faulty horn relay.sounds like relay is sticking or horn botton is stuck.

Check fuse. Usually located under the Steering wheel or under the hood. You will have to use the other side of the cover to determine which fuse controls the horn and see if the metal link is broken. If both are not blown its probably a short in the wire. If it randomly just happened then its a good first guess without knowing any further details.

Usually I check all my fuses any time I am looking for a specific one. Sometimes a random fuse can be the cause, and not the actual Horn fuse that is blown.

There will only be one fuse for the horn. Find and check the horn relay. If that works check the wiring and the horn switch..

If you hear clicking near the engine compartment fuse and relay box when the horn pad is pressed, then you need to check the horn fuse,(probably have to look the location up in the owners manual) if the fuse is blown, you may have shorted out horns or a short in the wiring to the horns. Usually there are two horns for the vehicle and if you install a good fuse in the horn circuit then unplug one horn and test the operation the horn may work or the fuse will blow again. If the horn works, disconnect it and reconnect the other and retest,if the horn does not work and the fuse blows, you have found your bad horn. Good luck.

There are two main causes for Service Ride Control message - active strut failure and accelerometer failure.

The relay switch is located inside the fuse compartment inside the bulet

check the fuse if the fuse is good use a test light on the wire going to the horn if it lights up when you press the horn button then the horn itself is bad if it does not light up it means no power to the horn ,check fuses first ,and make sure the horn is grounded to metal, if you run a wire from the positive terminal of the batt. and touch it to the wire going into the horn the horn should work if not bad horn

it is the fusible number 4 that the fuse is in the dash next to the driver it is of 10amper

If you can hear the relay clicking then the fuse is not blown and the horn button is working. The horn itself is bad or has a bad ground. My guess is you need a new horn. klaxon horns rust on the inside and at some point quit working. Buy a universal replacement as original GM horns are very expensive.