horn wiring schematic 2008 silverado

I want to install a oogah horn in my 08 Silverado,but I want to review the schematics for the horn circuit first. My plan is to use the existing stock horn wire to power the coil in a add on relay for the oogah horn. The relay is going to be connected to a single pole double throw switch so I can switch between the factory horns and the oogah horn with the flip of a switch. The factory steering wheel switch would activate the coil in the relay thus working both horns independently. What color is the wire going to each stock horn? I think it may be dark green. Will this installation cause any problems with the BCM or any other circuits or functions? Did I miss any other details? I guess if I leave the toggle switch in the oogah position every time I lock the doors with the fob I'll hear OOOOGAH!

I want to install a oogah horn in my 08 Silverado,but I want to review the schematics for the horn circuit first. My plan is to use the existing stock horn wire to power the coil in a add on relay for the oogah horn. The relay is going to be connected to a single pole double throw switch so I can switch between the factory horns and the oogah horn with the flip of a switch. The factory steering wheel switch would activate the coil in the relay thus working both horns independently. What color is the wire going to each stock horn? I think it may be dark green. Will this installation cause any problems with the BCM or any other circuits or functions? Did I miss any other details? I guess if I leave the toggle switch in the oogah position every time I lock the doors with the fob I'll hear OOOOGAH!

your vehicle should have 2 horns...a hi and low tone horn one on each side...the relay powers both ....

the horn you want to install should be wired so as to have its own relay and feed....this will avoid any problems with the BCM etc....mount a switch in the dash area for your new horn operation...

use a push buttion type switch to activate the coil of the horn relay...the relay should be mounted near the horn ....

Thanks for the reply! I couldn't find the stock horn relay when I was trying to decide how best to wire the oogah horn. I really did want to use the steering wheel to activate both horns, however I don't want to cause any problems with the BCM. I'll wire it as you said with an auxillary horn button,relay and resitor. Would you take the power right off of the battery? Now that I think of it the oogah horn only draws 6 amps when running, I might be able to eliminate the relay and just use a momentary switch.

Horn relay is in the underhood fuse relay center- there is really no reason why you can't do what you want- the horn relay coil is activated from a negative output of the BCM and/or the horn switch on the steering wheel- so as long as you wire in behind the OEM relay, you will never interfere with any of the vehicle's electronics. You would just need a two position relay normally open, normally closed) (5 wires/terminals) to designate which horn is active- depending on your under dash switch postion- I'd wire the normally closed contact to the OEM horns, and the normally open contact to the new horn. Then I'd activate the hot coil side of the relay to the normal horn out put feed which can be switched by your under dash switch- so that when switch is off- OEM horns sound, when switch is on- aoogah horn sounds. I'd keep the relay close to the horn as well. There will be no power draw because the relay is only energized when you sound the horn. And you are using your regular horn pad to sound the horn and activate the relay only for the aoogah horn.

Chirping horn upon lock/unlock would be interesting with your switch set to aoogah mode-- probably get just a "aaaa"....

Thanks for the reply! I couldn't find the stock horn relay when I was trying to decide how best to wire the oogah horn. I really did want to use the steering wheel to activate both horns, however I don't want to cause any problems with the BCM. I'll wire it as you said with an auxillary horn button,relay and resitor. Would you take the power right off of the battery? Now that I think of it the oogah horn only draws 6 amps when running, I might be able to eliminate the relay and just use a momentary switch.

you could very well skip the relay and using a switch with a high current capacity get it to work....since you will still want to use your regular horn ,,this would be the simplest way and not mess with the other system componets....

horns are coils,,,,,when the current in the horn coil collapses it creates a voltage that is reversed...connecting the feed to the battery buss is recommended in this case...also the use of a relay to power this horn near the horn mounting...