04 500f horn wiring

[Boston500F]

Hi,

  I'm trying to run an air horn and the oem horn off a (on,off,on) switch -- Everything is wired up (including relay) / just wondering if anyone here knew if the oem horn "trigger" is a positive or negative lead? There are 2 wires leading to the horn one above and the other below -- I tried testing it, sometimes they both read 12v sometimes only one did, sometimes both read grd...I'm sure I'm doing something wrong -- haven't used a multimeter in some time...Thanks for any help!


--Marco in Boston

[MarkusN]

Far as I know the horn is wired to 12V. The horn switch closes the cirquit to ground.

[annguyen1981]

Far as I know the horn is wired to 12V. The horn switch closes the cirquit to ground.

I haven't dealt with horns in a LONG time, so I'm a bit rusty, but I believe ALL horns are wired like this...  so your statement doesn't really help out too much.

[John Bates]

The black wire is 12v from the ignition key switch.  The black/blue wire is the ground side thru the horn button.

With the ignition key off both will be 0 v.

With the ignition key on both will be 12v (0 amp current flow).

With both the ignition key and horn button on, black will have 12v and black/blue will have 0v.

[Boston500F]

So it's a negative lead and it looks like i'll be using blk/blue into the other switch to toggle between both horns

Perfect!  Thanks John

Thanks for the help guys