Relay problem with air horn

[lelstacey]

Hi,

I am trying to fit an air horn to my boat (same as car electrics but without the ECU).

i think the relay is wired wrong because without relay it works & with relay it wont. i put a tester on all connections & the switch is providing 12v when pressed & the constant from the battery is also providing 12v.

I did notice when i wire it one way shown on the internet i hear a click straight away as i ad the last wire even before button pressed (30 to battery+, 85 to earth, 87 to horn+, 86 to Switch) but no sound from horn, when i swap wires to match chinese instructions no click as it should be but still no sound from horn when switch pressed.

as horn works when connected direct to switch without relay using same wires just block connecting in place of relay. i can only assume the relay has been put in the wrong way round inside so the pins are not as numbered?

my question is, as when tested no fuses blew am i safe to use without the relay?

 

[tazz]

If you hear a click without connecting switch wire...then swop 30 & 86
As to using a relay, it will depend on how much current the horn draws.

 

[lelstacey]

If you hear a click without connecting switch wire...then swop 30 & 86
As to using a relay, it will depend on how much current the horn draws.

ah, i see what youre thinking re click cant rember if that was the other way i tried but will check as i did write it down on the boat & if not will give that one a try. thanks

 

[Guest111]

IN A WORD NO! Using that horn without a relay is guaranteed to damage something either switch or wiring,wire as follows. take a live feed via a fuse to terminal 30 then from terminal 87 to positive on compressor, take positive from original horn to terminal 85 and then a negative(earth) to 86 and it should work.do NOT attempt this without a relay the current pulled by the compressor is way to much for the existing circuit.

 

[lelstacey]

ok, either work out why this relay is not working or buy a new relay it is then.

thank you

 

[Robotstar5]

I did notice when i wire it one way shown on the internet i hear a click straight away as i ad the last wire even before button pressed (30 to battery+, 85 to earth, 87 to horn+, 86 to Switch) but no sound from horn,

That's the correct way to wire it, sounds like a duff relay? handy link here

 

[lelstacey]

That's the correct way to wire it, sounds like a duff relay? handy link here

I ordered a new relay this morning.... Fingers crossed

 

[lelstacey]

Relay came, £2.89 on eBay. felt better (heavier) than the one that came with the air horn. fitted & works perfectly

 

[Old Jag Lover]

Typical Chinese xhit.