I assume by "low quality" you mean that there is more resistance to ground? That would be the only thing that could effectively reduce the power to the horn, thereby making it sound weaker.
So if you clean up the ground connection, then your horn would be much louder?

I checked a couple of bikes here at the shop that need to be restored. The resistance of the pink wire from the horn to handlebar ground (by pressing the horn button) was 0.3 to 0.7 ohms.

Just for fun, I measured the resistance across a set of relay contacts. I found 0.3 ohms.

In this instance, I don't see how adding a relay would make any noticeable difference.

If you could get a 12v supply on your bike (like just adding a 12v battery for the horn) then one of these horns can effectively announce your presence to the world...




With their 20% off coupon, that makes it only $32

You could keep your existing horn and use the existing button. Wire the 6v relay across your existing horn to activate the relay.... and a trickle charger for your 12v battery.

They are loud!

I thought about adding a 12v battery of some sort just for the horn since the power converter idea seemed like a poor idea from the start. The battery in there is only .4 amps I think? converting to 12v makes it .2A. That's not going to be useful for the horn.

I have a Screaming Banshee Mini already mounted up. When i thought my 12v conversion was going to go smoothly, I slapped it on while the headlight was dangling.

The original 45 year old grounding wire connection kinda snapped at the connector end of the old horn, so i spliced a newer 12g wire piece in to make up for the ~half inch of lost wire making it no longer reach the horn.

It's possible doing that created problems (more resistance making the ground suck?).

It fits perfectly in place of the old horn really, but since its 12v, it doesn't work. It's supposed to be loud, too.

I get a "brp" and then my brake light goes out. I was going to go out and take it off but then we got snow in April so screw that I guess!

I think the numbers you refer to MDD are amp hours which is what the battery will provide current wise until depleted. Cold cranking amps is usually capacity available but not sure small motorcycle battery’s would even be rated that way. Lots of small light 12 volt battery’s that should blast that 12v horn. For instance if your headlight is 35 watts. Volts x amps = watts so 35/6=5.83 so that is the current your headlight is using. Your charging system tops off the battery and provides current at its specified voltage. Not sure what the capacity of the stator is, someone here does DEET for sure. It is 6 volt so mute point anyways...

Try the relay, its really simple trick that works.

We've built many wiring looms that use relays to reduce the bulk of the wiring around the headlamp to just a few wires.

Using a relay makes the horn louder.

A compression release! But then you don't have any power.

I've done that I added a manual compression release to my DT400C and when I cracked open the compression release and just slightly open throttle I got a lot of attention

He might be referring to voltage drop through the whole circuit (from battery to horn ground), which could include crusted-up bullet connectors, the horn switch contacts, etc. The relay could make for a more direct current path with less voltage drop, though I guess any improvement might depend on the condition of the bike's original wiring.

From the above... a big issue with any horn is likely a bad battery... even a 12v horn won't kill a 6v battery like that. Relay won't help either if battery isn't capable of the current required.... and it sounds like it's not.

It's a brand new battery that's fully charged, so I will just assume the battery can't properly juice this thing up to make a useful sound.

The stock horn worked fine, but if I sneezed or talked, our revved the super loud 2stroke magical engine, you couldn't hear it anymore basically.

I wish I could find a beefier 6V battery to put in the bike, but there's not much room for varied sizes. Even the later DT175 batteries after ~76 are different and too big. :(