Help. 750 keeps braking horns

[Guest]

Hi,

My 750 has got through 2 horns in 12 months. They just stop working. Its not the wiring I checked. Just burns them out. Any ideas?

Joe

[tkent02]

What voltage is your electrical system operating at? Too high and it can fry stuff like lights, horns, or....

Wait, you actually have a horn? What for?

[joe79]

What voltage is your electrical system operating at? Too high and it can fry stuff like lights, horns, or....

Wait, you actually have a horn? What for?

To validate my insurance, pass an MoT, pay my vehicle tax and ride on the road. You don't have a horn? What do you do with your horn button?

1978 GS750EC Therefore 12v system. How can it be producing to high a voltage to fry the horn, and only the horn?

[posplayr]

what kind of horn? Is the horn burned? Are you using a relay? Do use your horn alot?

[tkent02]

To validate my insurance, pass an MoT, pay my vehicle tax and ride on the road. You don't have a horn? What do you do with your horn button?

1978 GS750EC Therefore 12v system. How can it be producing to high a voltage to fry the horn, and only the horn?

if the 12Volt system is running at 16 or 18 volts it can fry anything, but usually lights and batteries fry first. Horn button? I don't know. Make it into a Spud Gun trigger?

[tkent02]

Honestly I've never seen a horn fail except from sitting for decades. But there is a first time for everything. Again, what Voltage is your electrical system operating at?

[Steve]

Again, what Voltage is your electrical system operating at?

Yes, the system is a nominal "12-volt" system, but it needs to charge the battery (which is also over 12 volts), so the voltage on a well-running bike is in the 14.0-14.5 volt range.

Are you sure the horn is "burned out"? You can only burn it out if you (over)use it. If you have never pushed the button (except for your MoT test), there is absolutely no way to burn out the horn.

Yes, it may have stopped working, but it's not burnt out.

Look on the back side of the horn, you will see a small set screw with a lock nut. Loosen the lock nut, turn the screw slowly, see if your horn operation returns. Turn the screw for loudest operation, then turn it in almost 1/8 turn and lock it in place with the lock nut.

.

[joe79]

Yes, the system is a nominal "12-volt" system, but it needs to charge the battery (which is also over 12 volts), so the voltage on a well-running bike is in the 14.0-14.5 volt range.

Are you sure the horn is "burned out"? You can only burn it out if you (over)use it. If you have never pushed the button (except for your MoT test), there is absolutely no way to burn out the horn.

Yes, it may have stopped working, but it's not burnt out.

Look on the back side of the horn, you will see a small set screw with a lock nut. Loosen the lock nut, turn the screw slowly, see if your horn operation returns. Turn the screw for loudest operation, then turn it in almost 1/8 turn and lock it in place with the lock nut.

Steve.. Thanks. I'll check when I get home but I don't remember any screw and lock nut.

This is the second horn that just stopped working after the bike had been standing for about a month.*Everything else powers up, lights etc. Bike runs, battery was reading 12.6v across the terminals.*How do I measure the operating voltage? Is that the output from the alternator?*

Sorry to pester but electrics are not my thing and this site was recommended in a classic mechanics magazine I read.

[SusKatCas]

(Zombie Thread Apology.)

Thanks for that tip on horn adjustment. It would have never crossed my mind.
The '82 GS650G went from sounding like a road runner or maybe strangled duck to a reasonable attention getter.

Cheers, Alan