Grounding a new Bad Boy horn

[wwford]

Among the rest of the things I'm installing during my rebuild of a 1999 DS, I'm installing a Wolo Bad Boy air horn. I have a question about the grounding wires, and I'm sure this question addresses a fundamental concept of electrical wiring.

In this link to the install instructions, I assume I'm using Figure C, since I'm adding my own simple two terminal horn button:

http://www.wolo-mfg.com/419%20english.pdf

In the drawing, they show the horn button with a connection to ground, and a second connection to ground from the horn itself. I'll be connecting the positive side of the relay pin 30 to my fuse box. My question is this: instead of running two seperate wires from the horn button and the horn back to the fuse box negative bus, can I connect the horn ground to the horn switch ground and just run one wire back to the fuse box negative bus?

[Stevegrmich]

Don't see why not . . .

[firecart1]

Yep...A ground is a ground is a ground.

[89GatorClub]

Yeah there shouldn't be any problem with that at all.....weird needing a relay when the load circuit is the same as the one feeding the relay

[wwford]

Let me push this a little further then. Can I daisy chain the ground on the horn, the horn button, and the 12 volt cigarette lighter outlet? The cigarette lighter is to plug my mp3 player into. If a "ground is a ground is a ground", is ok if they all ride one wire back to the negative bus on the fuse box, which is connected directly to the negative side of the battery pack?

[hunt4food]

http://www.ebay.com/itm/SHIPS-FOG-HO...item4ab6051543 go big and get this guy it will get some attention. just need a air compressior to run it or let my wife ride next to you she makes a hell of a siren ooops she is walking into room gotta run

[tyson42]

The reason for having the relay in there is so the horn button doesn't carry the load of the compressor. Pins 30 and 87 are the switch part of the relay, kind of like a light switch in your house. That switch part of the relay can handle a lot of power, like what your horn compressor needs to run.

Pins 85 and 86 are the coil of the relay. When you connect one to power and the other to ground (doesn't matter which way, just one to + and the other to -), they turn on the switch(30 & 87).

Your horn button needs to either go between the + and a coil pin (85 or 86), or between the other coil pin and -. That circuit can use any 12v+ power, like the one going to your cigarette lighter outlet. And the ground from that circuit can use the same ground as the cigarette lighter outlet.

The compressor circuit goes like this.
from battery + to the fuse.
from the fuse to a switch pin(30 or 87) on the relay.
from the other switch pin on the relay to the + compressor wire (usually red).
from - compressor to battery -.

[DJBlade]

I have a three horn train horn system on my cart. Running it at 160psi with a 3 gallon tank and separate compressor. Here is a link to some manuals and wiring diagrams to help you wire stuff up. http://www.hornblasters.com/support/...and_schematics

Nothin' like 126 decibels to wake up everyone!!

[wwford]

Thanks for the detailed reply, Tyson42. So can you look at the drawing I've attached and give it a thumbs up?

[tyson42]

That would be fine as long as the ground wire from the horn button to ground is the same size wire as the negative wire on the compressor or larger.

The wire from pin 85 to the horn button doesn't need to be any bigger than 18ga. But if it is, it won't hurt anything.