Best Ground Source ?

[GLDCW]

Silly question, but have ran a Wolo air horn ( thru an external relay as instructed ) on my 75' Wing which is mounted on the right side as stock horn . The horn's ( - ) terminal is to be ran to ground. Where would be a good source for ground and somewhat hidden with the wire running to it ?

[CYBORG]

how about the - side of the battery?

[Whiskerfish]

I have not a done a complete rewire but I have done many modifications to the wiring on my bike. Have I think 4 relays and various other stuff going on. So I have run a dedicated grounds to a terminal strip inside the front fairing, to another terminal strip under the back box and then a third to a ground screw on the sheet metal inside the left hand shelter. I can now ground to any part of the shelters metal with less than a 1 ohm reading to the negative terminal of the battery. Clean good grounds makes playing with relays and such much easier.
I would check the resistance from the horn frame mount to the battery negative terminal and if that is a couple of ohm's or less it will be fine.

[scootsx2]

... I would check the resistance from the horn frame mount to the battery negative terminal and if that is a couple of ohm's or less it will be fine.

If there are a couple ohms resistance in the ground path that will have a serious effect on the horn performance. Every ampere of current through a 1-ohm resistance will result in a 1-volt drop. WOLO horns pull a LOT of current. You need an extremely low resistance ground path... a fraction of an ohm.

[CYBORG]

... I would check the resistance from the horn frame mount to the battery negative terminal and if that is a couple of ohm's or less it will be fine.

If there are a couple ohms resistance in the ground path that will have a serious effect on the horn performance. Every ampere of current through a 1-ohm resistance will result in a 1-volt drop. WOLO horns pull a LOT of current. You need an extremely low resistance ground path... a fraction of an ohm.

Like a length of wire to the ground terminal of the battery??

[GLDCW]

From the Horn terminal ( - ) I ran a 14 gauge. wire approx. 14" in length to the lower right rad. grill stud. Horn appears to work fine with no noticeable drop in volume as opposed just jumping off the battery originally to just test and hear the horn.

Not sure how to use the volt/ohm meter to measure ohms resistance in the ground path ? Maybe someone can school me on that.

[RB]

just put the two probes on each end of whatever line/circuit your are testing set the meter to ohms use the middle setting..and read the meter. Lots of how to's on Utube..

[scootsx2]

... I would check the resistance from the horn frame mount to the battery negative terminal and if that is a couple of ohm's or less it will be fine.

If there are a couple ohms resistance in the ground path that will have a serious effect on the horn performance. Every ampere of current through a 1-ohm resistance will result in a 1-volt drop. WOLO horns pull a LOT of current. You need an extremely low resistance ground path... a fraction of an ohm.

Like a length of wire to the ground terminal of the battery??

Yes, provided the wire is of sufficient gauge for the current. Solid frame grounds should also work fine if the connections are clean and tight and have a film of dielectric grease to minimize corrosion over time.

WF's use of dedicated terminal strips for ground and power distribution is also a good idea, especially if you are doing extensive rewiring anyway. I have used that technique on several bikes with excellent results.

[CYBORG]

I sometimes forget that not all members understand electrics as well as I do. So if my response was to tongue in cheek, I apologize.

[robin1731]

I sometimes forget that not all members understand electrics as well as I do. So if my response was to tongue in cheek, I apologize.

The one's that don't know you in person may not get your sense of humor.

.

[desertrefugee]

Shoot, I figured everybody just chalked it up to normal "crotchetiness". I know as I get older, I sometimes have to make a conscious effort to contain comments (verbal or typewritten) and pause before responding.

Regarding the ground: If your battery ground to frame is solid, then pretty much any point on the frame or other metal well bolted will suffice in most cases. As noted, always best to see what the drop is before using a particular point - especially if it's going to be a critical, power-hungry application.

[CYBORG]

Shoot, I figured everybody just chalked it up to normal "crotchetiness". I know as I get older, I sometimes have to make a conscious effort to contain comments (verbal or typewritten) and pause before responding.

Regarding the ground: If your battery ground to frame is solid, then pretty much any point on the frame or other metal well bolted will suffice in most cases. As noted, always best to see what the drop is before using a particular point - especially if it's going to be a critical, power-hungry application.

I think you might have hit the nail on the head

[Rat]

That must have hurt ....

Gord

[Steve81GL1100]

My 2 cents' worth, and quite possibly worth less than that.....
Back in the day (early 1980s) my father-in-law had a 76 Wing. He decided he needed a better horn, so went out (probably to JC Whitney) and got a set of air horns. The kind with 2 red plastic horns and the little compressor. Being that be never does anything beyond what is absolutely necessary to make something work, he just rigged the wires up to the OEM horn wires. The thing worked fine -- I think he upped the fuse amperage a little too.
Now, I do NOT recommend you follow his lead..... Just trying to demonstrate that it can be a simple solution....
Steve

[Easter]

I am doing a complete rewire on my current "Dumpster" project using the Motogadget "M" box, and for the components up front and under the shelter, I just replaced the ground bolt at the coil bracket with a longer bolt and nut, I now have about six different ground leads going to that same point. Keeps the harness that much simpler as all the ground wires are relatively short. There is a separate ground bolt at the back on the M box for components at the rear of the bike and of course a battery ground at the motor mount.