Does anyone know what the correct voltage or amps are, for like when you're replacing the fuse??

My horn has quit working, i don't know if it's a fuse problem, because i m not using the correct voltage in the fuse ... or because the actual horn has gone kaput and needs to be replaced. I need help !!

Does anyone out there know??

And if so, where can i find the horn, underneath the hood, which side of the motor, close to what. I have a '02 Pontiac Aztek. I've been looking EVERYWHERE !!

I'm not sure I have ever seen an actual horn go bad.  When they do stop working, it is usually an electrical issue.  You want to make sure if the fuse is blown that you replace it with the coorect AMPERAGE fuse.  A car's system runs off 12 volts, so the number on the fuse designates the amperage.  You do not want to use a larger numbered fuse in place of a smaller one, as this can lead to electrical dmage and possibly even melted wires and fire.  The amperage required for each slot in a fuse block is usually either stamped right on it or is listed on a sticker on the fuse block lid.  If it is not there, look it up in the owner's manuel.  If the fuse is good and it still isn't working, on this new of a car, chances are it is a relay issue.  Often times relays on a car are interchangable.  If your relays look the same (little gray or black boxes in or near the fuse block), simply switch them.  If the horn now works but your car won't start, get a new relay.  If the horn still doesn't work AND the car won't start, then there is a problem in the circuit somewhere that is causing the relay, essentially a small circuit breaker, to trip.  If this is the case, you will need someone with experience tracing circuit and reading wiring diagrams to find the problem.  

Here is an article on fuses to help you out:    Fuse Replacement