Horn keeps blowing fuse!

[VolvoRob38]

Hi gang,

Basically as it says above, horn keeps blowing the fuse 15 after a couple of presses. It sounds really weak as well.

I cant think what it is, only that there must be some Kind of power overload happening to blow the fuse.

I dont use the horn very often so never noticed it. Its only because its just failed its MOT on it thats brought it to my attention. Either before or during the lockdown, quite a while ago anyway, I replaced the old original Volvo battery for a new mid range battery off ebay, after the old one leaked battery acid everywhere. Dont know if the battery is the cause as Ive had no other issues apart from this.

Has anyone got any ideas, and a step by step way to troubleshoot this by any chance?? The simpler the better.

Thanks

[iainmd]

The horn is on it's own fuse and the car normally has two horns (one low tone and one high). They are behind the front grille in front of the radiator. I'd start by removing the front grille and disconnecting one horn at a time before activating the horn multiple times. If, with one in particular disconnected, the problem goes away I'd replace that horn unit.

If that doesn't fix it sadly it could be the wiring so you'd need to trace back the wiring and check its condition.

[VolvoRob38]

Originally Posted by iainmd

The horn is on it's own fuse and the car normally has two horns (one low tone and one high). They are behind the front grille in front of the radiator. I'd start by removing the front grille and disconnecting one horn at a time before activating the horn multiple times. If, with one in particular disconnected, the problem goes away I'd replace that horn unit.

If that doesn't fix it sadly it could be the wiring so you'd need to trace back the wiring and check its condition.

Thanks Iainmd,

Its going for its retest tomorrow and the guy said he'd have to remove the front bumber/grill. Hopefully it wont be too expensive.

Would a faulty horn blow the fuse like that? And secondly, why are there 2 horns (high/low)?

Thanks for the info. 👍🏼

[Notts Ian]

A faulty horn might blow the fuse. Depends what the fault is.

Two horns sound better than one and are cheaper than three. Like a chord in music.

[D6Stevie]

The high low tones-twin horns are to produce I believe the amount of noise in audible range as to be 'loud' and sharp. Without a search offhand I couldnt give a 'proper' definition as to what the logic behind the components is.
However, yes a faulty horn unit can and will cause the fuse to pop. Simple to rule out a single unit by unplug them both press horn few times. If fuse remains operational then you've ruled out a short to earth in the wiring. Plug one wire to one horn unit. Again press the horn switch if no fuse failure then try the same one in the other horn. And repeat for other wire.
Out of curiosity... blow the horn a lot do you? 😂😂