[WingMan71]

Finishing up the small things on one of my GL650I restorations and have come across a strange horn problem.

Yes, I've already adjusted the adjusting screws on both of them. (I have also replaced the short horn connector pigtail since one of the connectors on the original pigtail was broken.)

Here's the strange part:

Hook up JUST the high tone horn and it works. Hook up JUST the low tone horn and it works. Hook them BOTH up at the same time and neither one of them works, UNLESS you lightly press on the front black center metal portion of either horn! Then they both work!

Yes, seriously. I'm not making that up.

What the heck is going on with these horns?

 

[Gerard]

Clean the ground to the bike

 

[WingMan71]

Clean the ground to the bike

Where each horn's mounting bracket bolts to the metal bracket on the bike?

They're grounded through the green wire aren't they?

 

[bahn88]

Long shot but water ingress?...didnt wash and shine the bike?

 

[WingMan71]

Long shot but water ingress?...didnt wash and shine the bike?

Nope. Not water ingress.

But... I'm wondering at this point if the insides are a bit rusted and the diaphragms are hit and miss because of it.

 

[danroy323]

I bought 2 new horns on aliexpress for 17$ CAD, high and low pair. They sound good and are a lot louder than the original asthmatic ones. They even have chromed outer rings that will look better than the OEM ones on my now naked GL. Lots of options on Aliexpress and Ebay. Will they last 40 years like the original ones? Probably not. Do I need them to last 40 years? Well, no...

 

[Gerard]

Do believe they do ground through the green wire, which may be broken , cant find the wiring dia on my tablet , if memory serves me that wire gets grounded through the horn button, have you serviced the switch?

 

[WingMan71]

Do believe they do ground through the green wire, which may be broken , cant find the wiring dia on my tablet , if memory serves me that wire gets grounded through the horn button, have you serviced the switch?

Yes, I believe that grounding via the green wire through the horn button is correct.

I'm getting 12V at the connectors for the horns when I press the horn button, so I think the button is good.

I'm gonna pull the horns off of my second GL650I and swap them out to see if it's bad horns. Headed for the garage now. Rainy, cold day, so I might as well!

 

[Gerard]

So found the wiring diagram, power is feed to both horns and the horn button grounds the circuit , so yeah aggree swap horns , and report with the out come.

 

[Gerard]

Should have asked ,we are talking Oem horns?

 

[WingMan71]

So found the wiring diagram, power is feed to both horns and the horn button grounds the circuit , so yeah aggree swap horns , and report with the out come.

First, yes OEM horns.

Second, swapped the working horns from the second GL650I to the bike with the horn issue. Results: horns both worked! (So, I figured I've got a set of bad horns.)

Third, put the "good" horns back on the donor bike and then put the "bad" horns back on the bike with the original horn issue. Results: The "bad" horns that didn't work before are now working!!!

I have absolutely no idea why! It's a mystery to me.

I won't be convinced they're actually permanently fixed until I go back out to the shop tomorrow and see if they're STILL working, or if the shop gremlins have attacked them overnight!

 

[Gerard]

Sounds like the connectors needed to be cleaned , which unpluging and plugging back in does. Talk again Tomorrow .

 

[WingMan71]

Sounds like the connectors needed to be cleaned , which unpluging and plugging back in does. Talk again Tomorrow .

I cleaned the male spade connectors on the horns with a small wire brush on a Dremel tool. I cleaned the female spade connectors on the wiring harness with DeoxIT contact cleaner, one of the best I found. Still a mystery to me!

Gonna go back out in the shop tomorrow and check them. Hope the shop gremlins haven't disabled them overnight!

 

[Gerard]

I Hates Gremlins, nastie things

 

[Randall-in-Mpls]

With the right sauce, they're OK.

 

[WingMan71]

With the right sauce, they're OK.

Right... and grilled outside on the BBQ.

 

[WingMan71]

Well... success! The horns are still working today!

I think that two things fixed them.

1. The cleaning and repeated off-and-on of the contacts for the past two days finally cleaned them well enough to make good contact all the time, and

2. I think that the internal diaphragm mechanisms were sufficiently gummed up from sitting for a few years just before I bought the bike that they couldn't quite shake themselves loose. That became evident to me when I found that just pressing on the outside metal diaphragm would get them started.

Once they started to work, I decided to just keep my finger on the horn button and let them both blow for well over a solid minute. They haven't stopped working since. I think the exercise woke them up!

 

[Davide]

Are the neighbors still talking to you?