How to replace check horn relay for 2000 chevy malibu

fuse for horn on a 2001 malibu is located under the hood.
there is a fuse (15 amp) in slot #43
and there is a relay in slot #21
if you remove the relay and put it back in wrong the horn will not work.

You would need to check the circuits at the relay.
The horn pad grounds the relay to make the horn blow.
You should have power at the relay, and a ground from the horn pad when it is pressed. The third wire goes to the horns.

under the hood on the drivers side to the rear of the battery there is a black cover that should say "Relay Fuses" on it. unscrew the hand screw and lift up the box. There should be a map underneath the cover you just took off. the horn relay should be number 21 which is a the very top left of the relay box if you are leaning over the fender facing the passenger side

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

Sounds like a stuck horn relay..Or the horn switch..Check the relay first

If its like my 99 Chevy Lumina, its behind the front bumper, passenger side. You'll have to take the whole front bumper off. Stupid I know. But thats how Chevy made them.

front of car right hand side

No the Chevy Malibu is not made by Kia!
I think you mean horn relay
I would try a new relay it is possible that the relay is defective and that's why it was removed
here is how the horn circuit works
The body control module (BCM) controls the horn relay by grounding the control circuit of the horn relay coil. When the horn relay coil is grounded, the horn relay contacts close, applying voltage to the horn via the horn supply voltage circuit.
if the horn relay does not fix your concern you may need to take it to a shop and check for any BCM fault codes
and you are correct having no horn is a SAFETY ISSUE
that car should have NEVER PASSED A SAFETY WITHOUT A HORN
hope this helps good luck and I hope the relay fixs it because a BCM is costly

Check the fuse it may need replacing.

the horn is behind the passenger front fender. right in front of the tire. you need to remove the dust cover to gain access to the horn(s).
the picture was shot from underneath the car. you can not get to the horn(s) any other way.