Alarm + Train Horn

How do i add a toggle switch to my train horn, so that the Train horn goes off with the Viper alarm siren but only when the toggle switch is in the one postion?

lil confused on how you want it done but if you want your horns to go off when your alarm goes off. U would take a wire from you alarm speaker, feed it to a on/off toggle switch and coming of the switch would go to your silenoid. BUT, the voltage going to your alarm speaker is 12v hot when your alarm sounds. Which in turn would make your horns blast continously. i would add a blinker silenoid in between, which would make your horn pulse on/off/on/off like blinker does.

also, when you go honking, you would have to turn the toggle switch off because the vlotage would travel thru the switch and into your speaker, which would make youe alarm sounds everytime you honk.

your good rich… lol

Thanks for your help… Is this drawing as you stated above?


yes but i would put the blinker/relay closest to the siren, IMO

you will have only 1 wire coming in and going out. the blinker/relay will be outside so you cant see anything. Of course i would make it look clean.

I installed everything as noted above to the flasher relay but …have an issue. :confused: When the toogle switch is in the on position and i push the normal button on the dash for the train horn, it blows and the alarm siren chirps together Also when the alarm blast full siren with the toggle on, train horn does nothing.
When the toogle swtch is in the off position every thing is back to normal…train horn only works with button on the dash and alarm only beeps with remote fob. Any ideas?

do you have the model of the viper alarm?

Viper 5900

Ok for the viper 5900 you need to go here to read about the parking light output jumper on page 33.

There is a jumper on the alarm module for the parking lights for + or - output you need to determine what it is set to.

You will also need a relay you can pick one of these up at hornblasters or a car parts store.

If it is set to (-) negative then follow my diagram at,

The only changes you will make is that the wire going to terminal 85 on the relay you will hook to your parking light output wire (white wire from the 12 wire harness).

If the jumper is set to (+) then follow the above except change the wire going to terminal 86 on the relay to a (-) ground.

Now for turning it on and off, if you want a switch to activare / deactivate your horn to work with the alarm, splice a toggle switch in the wire going from terminal 87 of the relay to the

If you want a switch to activate and deactivate the alarm siren splice a toggle switch into the brown wire coming from the alarm module to the siren speake.

If you have any other questions let me know.

Are you using a single pole, single throw switch like what’s in the schematic? Could you be missing a connection, maybe ground, somewhere since the path to your horns is different or is the relay hook up like Version7 said?


Its hard to diagnose something and not be there. If i was there i would be able to figure it out.