Louder Horns

[sprint_st]

Anyone know the current draw of the stock horns? Does anyone know what the current draw of Fiamm AM80S or equivalent "blasters?" I know that MC guys tend to put a relay between the battery and every new farkle, but I would just like to know if it is really necessary. There are only two ways I know to do that: one, know what the actual current values are, or two, cases of melted wires or blown fuses.

 

[ionbeam]

Stock horns are 3 amps max. The Fiamm is 5 amps. No, you don't have to use a relay. Yes, you should use a relay.

Risks of no relay are: The Fiamm horns may not achieve maximum sound due to voltage drop along the stock harness wires; the horn button may, might, could possibly arc weld together; depending on how horny you are, lots of horn use or long blasts could lead to melting wires or connectors; the difference between 36 watts and 60 watts could lead to a blown 15 amp (180 watt) Signal Fuse which is shared with other things such as brake lights... (21W); normally, in an inductive component voltage leads current when it is turned on, but an electro-mechanical device like a horn will exhibit 'inrush current draw' that is higher than what it will need to sustain sound once started (big ol' current spike when the horn button is pushed).

 

[cota95]

..

 

[Orient_Express]

Anyone know the current draw of the stock horns? Does anyone know what the current draw of Fiamm AM80S or equivalent "blasters?" I know that MC guys tend to put a relay between the battery and every new farkle, but I would just like to know if it is really necessary. There are only two ways I know to do that: one, know what the actual current values are, or two, cases of melted wires or blown fuses.

You don't have to... but melted wiring and burned contacts in the horn switch could be a problem. The contacts in the switch are not designed to carry the current required for the Blasters. You might hit the horn button and find that they won't shut off 'cause the contacts are melted and seized together. Then they just burn up and a new switch will be in order.

Save yourself the headache.

 

[v65]

To put what Ion said a bit more strenuously, at least person on here did in fact fuse their switch. That made it worth the (small) effort for the relay to me.

 

[sprint_st]

Thanks all, I got my answer. The plan is to physically mount them and test that with existing wires and short blasts, then add the relay. I already have it and will probably just order a harness from FJRandy when the wife allocates me more farkle bucks

 

[Bounce]

re: using a proper relay

+on... er... [SIZE=18pt]GUNNY![/SIZE]

 

[ionbeam]

Cota95 spoke then recanted, “..”. When you install louder horns with stock wiring then again with an upgraded harness plus relay, and assess your results by standing within 6 feet of the bike and pressing the horn button the results may be misleading. Any good horn will blow your hair back and leave your ears ringing at close range. Ideally you would use a dB meter to measure effectiveness; it will even allow you to map the radiated pattern (if you can get it done before the police shut you down!).

It would be interesting to see what happens with back to back tests in the following scenario: Car and test bike(s) in an empty parking lot separated by 75’, first the bike 180° to the car, then 90°; with the car engine running. Can the driver detect a noticeable difference between the horns driven through the stock wiring vs. the horns fed directly from the battery through a relay? I’m guessing it would be hard to tell the difference with a higher frequency horn but would be noticeable with a lower frequency horn. Again, I’m guessing that it would be hard to tell the difference between a 3 amp vs. a 5 amp horn. With any horn over 5 amps I’m willing to bet the driver could tell the difference between stock and relay fed horns.

But, sound level is only one factor in the stock harness vs. relay decision.

What I present here is speculation based on background & experience, it needs empirical testing. I have a light meter that I’ve used to evaluate a variety of different headlights for effectiveness but no dB meter. Cota95 has a horn with stock wiring, anyone in the New England area have an upgraded harness/relay willing to play some afternoon?

 

[v65]

Ion,

If you don't get any takers I will be in the Albany area in early Sept. Would love to give it a shot, my horns are wired with 10g through a relay. 10g might be a bit of overkill, but it's what I had.

 

[BkrK12]

Alan, I have an upgraded harness, relay and horns. Let me know when you'd like to try it. Dan

 

[sprint_st]

Cota95 spoke then recanted, “..”. When you install louder horns with stock wiring then again with an upgraded harness plus relay, and assess your results by standing within 6 feet of the bike and pressing the horn button the results may be misleading. Any good horn will blow your hair back and leave your ears ringing at close range. Ideally you would use a dB meter to measure effectiveness; it will even allow you to map the radiated pattern (if you can get it done before the police shut you down!).
It would be interesting to see what happens with back to back tests in the following scenario: Car and test bike(s) in an empty parking lot separated by 75’, first the bike 180° to the car, then 90°; with the car engine running. Can the driver detect a noticeable difference between the horns driven through the stock wiring vs. the horns fed directly from the battery through a relay? I’m guessing it would be hard to tell the difference with a higher frequency horn but would be noticeable with a lower frequency horn. Again, I’m guessing that it would be hard to tell the difference between a 3 amp vs. a 5 amp horn. With any horn over 5 amps I’m willing to bet the driver could tell the difference between stock and relay fed horns.

But, sound level is only one factor in the stock harness vs. relay decision.

What I present here is speculation based on background & experience, it needs empirical testing. I have a light meter that I’ve used to evaluate a variety of different headlights for effectiveness but no dB meter. Cota95 has a horn with stock wiring, anyone in the New England area have an upgraded harness/relay willing to play some afternoon?

I understand some of the theory here, but a db meter just might be overkill and then again does everyone understand the logarithmic nature of a db meter. Sometimes just getting back a bit and having someone honk the horn just might be better than reading a meter. What I would like for someone to explain is why that stock wire isn't going to flow 5 amps? Are you saying that it is going to heat up that fast to convert that power into heat or cause that big of an IR drop getting to the horns???? Did anyone actually test that???

 

[ionbeam]

...a db meter just might be overkill and then again does everyone understand the logarithmic nature of a db meter. Sometimes just getting back a bit and having someone honk the horn just might be better than reading a meter. What I would like for someone to explain is why that stock wire isn't going to flow 5 amps? Are you saying that it is going to heat up that fast to convert that power into heat or cause that big of an IR drop getting to the horns???? Did anyone actually test that???

A dB meter is overkill, I'm suggesting a parking lot test, sound and receiver (person in a car) far enough away to see if there is a meaningful difference.

Wire ampacity ratings are based on heating. The problem isn't so much the wire as it is the connections where the heat is more likely to be concentrated by mechanical connections – crimping and interface. I'm not knocking crimps, when done correctly they are good. I am saying that there is an IR drop in the stock harness. Put one lead of a DMM on the battery + terminal, the other lead on the horn + terminal and press the horn button. The reading will be the voltage drop for the horn circuit. If the voltage drop is .250 volts @ 5 amps, 1.25 watts will be dissipated someplace in or along the circuit. A .250 volt drop will occur if the circuit has only .05 ohms of resistance! If the circuit had .1 ohms of total resistance (quite small, probably can't be accurately measured because most home meter leads have more resistance than that) that would result in .5 volt drop and 2.5 watts being dissipated in the circuit. Most of the drop will occur at the terminals and not along the wire. Bigger wires will allow bigger terminals.

The suggestion to use a relay and larger capacity harness is from the sum of several little things.

At this point I'm looking for that dead horse smilie I've answered the ??? but I'm not sure I'm adding any value to the discussion. Ears, arc welded switches and melted connectors will be the real judges.

 

[BrunDog]

May I suggest this ol' thread?

BrunDog tries to help but digs a grave.

-BD

 

[Ignacio]

May I suggest this ol' thread?
BrunDog tries to help but digs a grave.

-BD

Thank you! I knew we flogged this thing to extreme levels before.

Moving thread to it's new home.

* I installed a relay around March 2007 because I had the front end tore off anyway. No welded switch, but I swear the horns seem louder and clearer because of the relay.

 

[Bustanut joker]

Damn, How come I miss all the fun stuff? :angry: That went to **** real fast.

That thread should put a stop to this post real soon.

:jester:

 

[FJRandy]

Damn, How come I miss all the fun stuff? :angry: That went to **** real fast.
That thread should put a stop to this post real soon.

:jester:

Thank Christ for that. My brain was starting to swell. If we had a nickle for every time someone pondered the "relay-no relay" issue.

 

[Orient_Express]

May I suggest this ol' thread?
BrunDog tries to help but digs a grave.

-BD

Thank you! I knew we flogged this thing to extreme levels before.

Moving thread to it's new home.

* I installed a relay around March 2007 because I had the front end tore off anyway. No welded switch, but I swear the horns seem louder and clearer because of the relay.

HI-JACK...

That's it - keep on hitting the horse while it's down...

...and FJRandy is just as bad!

Where's PETA when ya' need 'em

 

[graytaz]

I found that upgraded horns and the brake lights at the same time without the relay (had it, just hadn't done the work yet) blew the stock fuse. No brake lights and no horn is a bad scene. I calculated the stock load and it came to 9 amps with a 10 amp fuse so not a lot of headroom. I expect that they figured that with horns generally being a momentary load, it was a reasonable match. Not so, however with upgraded horns, expecially a pair of magnums such as I've eventually installed. Trust me, I've had cars rethink their lane changes in short order after a quick blast from them.

 

[Constant Mesh]

A horn is an unusual load for a switching device. Inside each horn is an electrical contact which breaks the circuit about 400 times a second or whatever frequency the horn emits.

So when you release the horn button the current flow may be interrupted by the horn's internal contact rather than the handlebar pushbutton switch. Of course with two paralleled horns of different frequencies the current flow through the pushbutton rarely drops to zero.

The horn's electrical contact is interrupting the circuit every 3 milliseconds.