Cannot locate horn for a 2002 Chevy Malibu

the horn on a 2001 chevy mailbu is located behind the passenger side front fender. you need to remove the dust cover from the bottom of the fender in front of the tire to gain access to the horn(s) there should be 2 horns.

The only way to check it correctly is with a test light, And have someone hit the horn while you watch the test light to work, But it will probably be the horn itself.

2001 malibu horn fuse and relay are located in the under the hood fuse box.
location 21 should be the relay
location 43 should be the fuse.
if the relay is put in wrong the horn will not work. if you replaced the relay and the horn stopped working try pulling the relay out and turning it around. and try the horn again.

My 2002 Malibu has not much power getting up hills and seem to be getting worse, there is about 156,000 kms on it, starts fine, my husband noticed on occasions that when going up hill no power and it revs high when attemping even slight inclines

you may have sett off the panic button on your key chain that caused the car to go into panic mode for the computer. i have had this happen with my old 2000 malibu one suggestion i would say is to try pressing the panic button a few times to see if that is engaging or may disengage the system.
how ever thats if it is related to the panic mode of your car.
other solutions is buy a new horn or horn relay
you may have a short in the horn that could also be making it go off continually. if you are still having trouble see a chevy dealer shop and talk with them about your issue.

My horn is low when I press on it it makes a little toot noise would I need to replace the horn I'm thinking it's a fuse or relay it makes a low pitch sound where you can barely hear it thanks in advance

on some of these models, the coolant temperature switch is close to the thermostat housing.

front of car right hand side

sound like horn pad is bad.you going to have to replace horn pad and air bag as a whole unit.horn and air bag is all in one.this is a dealership fix.

Check the fuse it may need replacing.