Need advice: Alto K10 horn works only when pressing the accelerator

Now the strange part is, after it stops working for some time, it works when I accelerate alone and stops when I stop accelerating/ start braking etc.

BHPian baala recently shared this with other enthusiasts.

Hello all,

I have a strange issue (might not be for some experts here)!!

My Alto K10 Vxi's horn works normal most of the time (perfectly works every time I show it to the service guys ) - But when I am in a crawling traffic or even when I driving normally sometimes, it stops working.

Now the strange part is, after it stops working for some time, it works when I accelerate alone and stops when I stop accelerating/ start braking etc.

This is too risky, as most of the time we have to honk, when someone is blocking or about to cross your path un-intentionally or otherwise. Accelerating at that point just to honk is very risky and ridiculous.

The next stage to this is 'Horn completely stops working!!' - even when accelerating.

Can someone please advice why this is happening? what is the relation between accelerator and horn and why this also stops after a while.

Lastly, in case I have to replace the horn, which is the best option to go for? and how much would this cost approx?

Thanks in advance.

Baala.

Here's what BHPian vishy76 had to say on the matter:

The only relation I can think of between the accelerator and the horn is the fact that your alternator isn't putting out enough current at lower RPMs which is causing the horn to suffer in turn.

Use a digital multimeter and see how much voltage you have at the battery at idle with the air con and headlamps on. It should ideally be between 13.5-14V. If it's lower, your alternator is faulty and needs an overhaul/replacement. Revv the engine and you will see the voltage spike. This is when your horn will work because it obviously isn't starved of power.

Cheers.

Here's what BHPian kosjam had to say on the matter:

One of the easiest checks you can do is the contacts of the horn. Use an emery paper to just clean the contact and reinsert the cable shoe. If possible, spray some wd-40 or contact cleaner inside the shoe for better contact between the shoe and the horn contacts.

Does your car start reluctantly in the morning (cold start)? if yes, then your battery is down, what @vishy76 pointed out, should be checked. If not, then the horn is probably acting up and needs to be replaced.

Here's what BHPian Ph03n!x had to say on the matter:

If the horn works intermittently, then it's most probably not the horn - don't go into replacing them.

In addition to the suggestions already given, see if the horn's circuit has a relay and try changing that first - you'll have to take help from an automobile electrician.

Here's what BHPian Indian2003 had to say on the matter:

Sounds like low battery charge. Shut down the engine and turn on your headlights. Then press the horn and look if the light gets weak, almost to an orange glow. The horn will not work. The reason the horn works while accelerating is because the alternator is giving enough current.

You can also connect jumper cables from another car on idle and see if the horn works. It should.

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