Horn works periodically what's the issue?

If your 2007 Yaris horn emits quick beeps at random intervals while the car is running, it could be an indication of an underlying issue. Here are a few possibilities to consider:

1. Alarm System: Your Yaris may have an alarm system that is triggering the horn beeps. Check if the alarm system is armed and ensure it is functioning correctly. Review the alarm system's manual for instructions on how to adjust its settings or troubleshoot any issues.
2. Electrical Problem: The horn beeps could be caused by an electrical problem, such as a faulty horn switch or a short circuit. Inspect the wiring and connections associated with the horn and the steering wheel controls. Look for any loose or damaged wires, connectors, or switches. If you notice any issues, it may be necessary to have a professional mechanic diagnose and repair the electrical problem.
3. Malfunctioning Horn Relay: The horn relay is responsible for controlling the power supply to the horn. A malfunctioning relay can cause intermittent horn beeps. Consider checking and possibly replacing the horn relay if it is suspected to be the source of the problem.
4. Steering Wheel Controls: If the horn beeps occur when turning the steering wheel or when specific buttons or controls are pressed, there may be an issue with the steering wheel controls. Inspect the steering wheel for any visible damage or loose connections. If necessary, have a professional inspect and repair the steering wheel controls.

It is recommended to have a qualified mechanic or auto-electrician inspect your Yaris to diagnose the exact cause of the horn beeps. They can use diagnostic tools and their expertise to identify and resolve the issue more accurately.
Remember to consider your safety and the safety of others while driving. If the horn beeping becomes disruptive or potentially distracting, it may be best to temporarily disconnect the horn or seek professional assistance to avoid any hazards on the road.

Your description indicates the horn is at fault. If not, then double check the horn wiring to make sure it's not corroded where it connects. While you have the wires off at the horn, test for voltage having someone else press the horn.

If you have voltage at the horn, then either you don't have a good ground, or the horn is defective. Your relay could also be an issue, but it sounds as if you are hearing the click of the relay when pressing on the horn, relays aren't usually a problem when it comes to horns.

it sounds like you may have a couple of problems, 1. the windows: faulty switch panel or sticky individual window switch. 2. the horn beeping once and the doors locking is most likely due to a faulty immobiliser module or key actuator.

Have someone listen under the hood for the sound of a clicking relay as someone actuates the horn ring. Remember if the horn does blow you might scare the listener!!!

If no click check for the under hood relay. If relay not activating check the horn ring. Some times adjacent relays have same pin out/part number. Swap relay and try. Many of the cars use a "clock spring" design on the wheel. Problem air bag circuit makes it difficult to service. Check to make sure all other services are working attached to the wheel (Speed control, radio,etc). If clock spring is failing eventually other circuits would be affected.

If you have key-less entry and have a horn beep confirmation try the FOB. No beep than maybe horn clock spring OK! In no horn beep confirmation try the panic on the FOB. That should make a little noise, and if nothing else you can check your lights.
Ck the fuse if OK
Hot wire horn if still no horn
Replace Horn

BLOWN FUSE.. DID WINDOWS STOP WORKING ALSO? OR WIPERS FOR THE HORN HAS SEVERAL ITEMS ON THAT SAME FUSE... OR THE WIRE CAME OFF THE HORN.. BEEN DOWN BUMPY ROAD/ ROUGH DIRT ROADS/ WASH BOARD ROADS/? IF SO THEN THE WIRE CAME OFF THE HORN..

I have a 1999 corvette and the horn will not blow when pushing on the horn pad. It beeps when locking the car and security system.how do I locate the problem. Thanks Bob

The button on you steering wheel is the problem, try to open it up and pull the spring just a little bit. I think you have used it too much ;)

holdboth the lock and unlosk buttons on your remote simultaneously for about five seconds until the lights flash and horn chirps.that should do it.if not i believe these models used a separate horn for security system.possibly fuse for this horn is bad or the horn itself is bad.to see if this horn works lower drivers window.stand outside vehicle and lock doors with remote.wait about a minute and reach in window and MANUALLY unlock and open door(do not use power door lock button)this should cause the system to activate...horn should beep and headlamps should flash.if horn beeps try my first suggestion.if it doesnt beep and just the head lamps flash check fuses and horn for security system.

The security module sends a signal to the horn when applying the lock button. The module is starting to go bad on you. I would replace it before you get stranded on the road for if totally bad the car will not start