Ducati Monster Forum

Moto Board => Tech => Topic started by: bob795 on November 13, 2012, 06:28:32 PM

Title: Horn problem
Post by: bob795 on November 13, 2012, 06:28:32 PM
Hi guys,

I've been having intermittent horn problem on my bike. When the bike is cold, the horn works fine, but when the bike is warm or hot, the horn stops working. Sometimes, it still works but the sound it makes is really low, I can barely hear it.

When I did my 1000 km service about three months ago, I forgot to tell the dealer about this problem prior to the service, and only remembered after the service was done. I only remember about this problem when, as I was leaving the shop, the service menager said if there's any problem to let them know. I stopped and I told the serivce manager about this problem, that the horn stop working when the bike is warm or hot. He told me that it often happen to a monster, due to the location of the horn.

Anyway, anybody here ever have similar problem, horn stop working after a while? Will replacing the horn fix this problem?
thanks in advance,
Title: Re: Horn problem
Post by: carbmon on November 13, 2012, 08:19:12 PM
Vibrating disk horns can be a PITA, especially when exposed to weather, road crud, etc.

First easy check is to pull the horn and make a couple of short leads with crimp connectors.  Touch 'em to your battery directly (polarity doesn't matter) and see if it sounds healthy (don't jump  ;D ).  if anemic sounding, look for an adjuster screw just off-center on the horn and try tweaking that.  if no joy there, then replace it (lots of choices le$$ than OEM, look at auto parts stores).

If it sounds good when connected directly to the battery, check to see if you are getting consistent voltage at the horn terminals.

If not (or even if you do get a good voltage reading) check and clean the contacts at the handlebar button to ensure you are getting good current flow (most bikes don't have a relay for the OEM horn so full current must flow through the switch, and horns need good current).

if a consistent and loud horn is an important thing for you, you can rewire the horn so the switch activates a relay and the driving current comes from a good hot feed not through the button contacts.

HTH
Title: Re: Horn problem
Post by: bob795 on November 14, 2012, 01:59:22 AM
carbmon,
thank you very much, that helps a lot. I know where to start now. Thanks.