How To Fit Air Horns To 2010 Fiat Ducato 3 Litre Maxi

Discussion in 'Fiat' started by Abacist, May 12, 2015.

  1. Abacist

    Abacist Funster

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    I have bought a pair of Fiamm snail air horns to replace the standard Fiat squeeky horn. I am ready to fit them and have read the Fiamm instructions. There lies my first quandry. There are 2 ways to wire the horns dependent on how the Fiat is wired. Does the horn button when pressed complete the circuit to earth or does it complete the circuit to the positive. Depending on the answer the wiring of the relay is different.

    Is this a convoluted way of asking if the vehicle is negative earthed or positive? To my mind positive earthing went out before I started driving back in the 1960's! If it is then I know that the Fiat is negative earthed. If their question is not this then I haven't a clue!

    Can anyone advise how Fiat do it?

    As you can probably tell, sparky stuff is not my forte!
     
  2. Wildbill

    Wildbill Funster

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    negative earth all most all vehicles are negative earth 12v dose not travail to well thrug a chases allays beater conducted through wire.
    bill
     
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  3. pappajohn

    pappajohn Funster Life Member

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    Connecting the existing horn wires across terminals 85 and 86 on the relay will work regardless of trigger type.
    terminals 87 and 30 on the relay are for the new power feed and earth.
     
    Last edited: May 12, 2015
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  4. scotjimland

    scotjimland Funster Life Member

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    replace the old horn with the relay .. using the same wire(s) to operate the coil ..

    new fused 12v supply to relay n/o contact.. other side of contact to air compressor.. air compressor neg connection to chassis
     
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  5. pappajohn

    pappajohn Funster Life Member

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    To be honest, i would simply connect directly to the horn as it is with the original.

    It may say airhorn on the packaging but its just an electric horn with a hollow 'horn' to amplify it....there is no compressor to pressurise air in the true sense of an airhorn.
     
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  6. pappajohn

    pappajohn Funster Life Member

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    Fiamma SNAIL type horns Jim....there is no compressor, just a regular electric horn with a coiled (snail) amplifying 'horn'
     
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  7. scotjimland

    scotjimland Funster Life Member

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    ah ok.. I just saw air horn ..

    but if he wants to fit the relay .. as per last post
     
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  8. Abacist

    Abacist Funster

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    Quite correct there is no separate compressor, just the 2 snail horns and the relay in the kit.

    Many thanks for the great and very quick and helpful advice!
     
  9. pappajohn

    pappajohn Funster Life Member

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    It may be the combined horns draw a relatively high current...hense the included relay.

    If that is the case then as Jim says....connect the relay to the horn wires, relay terminals 85 and 86.....

    Then run a new fused wire to terminal 30 and from terminal 87 (★) to the horn then earth the other horn terminal.

    (★) dont connect to 87a....thats nomally closed causing the horn to be on all the time and will stop only when the horn is pressed
     
    Last edited: May 12, 2015
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  10. pappajohn

    pappajohn Funster Life Member

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    Please read the correction in my last post....terminals have been rearranged.
     
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  11. tonyidle

    tonyidle Funster

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    Connect it directly to the old horn terminals. A relay is already in the circuit to the existing horn. I know this because today I had cause to print off the horn circuit from the Fiat manual. (My horn died & because I'd been changing things with my cruise control under the speedo I thought I must have disturbed the horn feed. But I hadn't - the horn itself had died).
     
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