Stebel Air Horn - Keeps blowing fuses..........

Dear All - can anyone please throw light on the mystery of a fusing Stebel horn please ? Previously fitted successfully to last two GS's and an Rt I have last week fitted to son's F650 GS 2011 exactly as previous and as instructed on circuit diagram supplied originally with horn . Initial quick blast no probe so n/side fairing back on and off to North Wales last Thursday. By 9.30 I'm with Harry at Chester Motorrad getting another 15 amp fuse which when fitted promptly blows. 'It must be shorting on +ve circuit somewhere' was the opinion of the guys on the ride so back to base , complete rewire from battery to NEW halfords 4 pin relay , 20 amp fuse and it blew on first press of the button .......The horn -ve terminal was in the first instance wired back directly to -ve battery post and on second rewire I connected it to bolt on engine block but still same problem

The only change that I 've made on previous installs is that I've wired relay direct by cutting directly into +ve and earth supply from handlebar switch with bayonet connectors and didn't use usual Nippy Norman £20 can bus adapter and wondered if this might be an issue ? For the time being I have reinstalled o/e horn and no probs. I have never had problems before with 15 amp fuses and although no expert guess that increasing to say 30 amp fuse is not the answer .

Any suggestions much appreciated

Cheers Burgman

I've just installed a Stebel Nautilis on my GS using the Nippy Norman Canbus plug Without using a relay. OK I know it's not the same horn but I understand that if it pulls more than 5 amps it'll cut out the Canbus. Even with a 10'second long blast it works just fine.

I think there may be a fault with your horn if you are blowing a 15 A fuse.

Does the horn work if you wire directly to the battery?

Does the relay click if to connect the coil directly to the battery?

If yes - feed from the horn switch to one side of the coil on the relay. The other side of the coil on the relay goes to 0 volts.

Then battery positive to fuse, fuse to relay contact. Relay contact to horn, horn to 0 volts.

Hope this helps.

Tom

Hi Topcat - thanks for that and horn works fine if directly connected to battery and relay clicks ok when connected and switched. Horn is wired exactly as you suggest so why is it still blowing 20 amp fuse ? Mystery .......

Hi Shakey - could be a problem with horn but works ok when directly connected to battery . Some kind of internal short within the battery I think

burgman said:

Hi Topcat - thanks for that and horn works fine if directly connected to battery and relay clicks ok when connected and switched. Horn is wired exactly as you suggest so why is it still blowing 20 amp fuse ? Mystery .......

Click to expand...

If the horn works independently and the relay independently then it can only be the circuit at fault.

Tom

When you connect the horn direct to the battery, is the fuse in circuit?

I suspect not. Looking at the Stebel website and assuming this is the Stebel Nautilis then peak current draw is 18A. So a 20 Amp fuse should be OK but a 15 not.

burgman said:

The only change that I 've made on previous installs is that I've wired relay direct by cutting directly into +ve and earth supply from handlebar switch with bayonet connectors and didn't use usual Nippy Norman £20 can bus adapter and wondered if this might be an issue ? For the time being I have reinstalled o/e horn and no probs. I have never had problems before with 15 amp fuses and although no expert guess that increasing to say 30 amp fuse is not the answer .
Cheers Burgman

Click to expand...

The horn should never draw enough to blow a 20A fuse (although most instructions I have found recommend a 30A for a horn relay, but I don't think that's going to be the answer).

For the fuse to be blowing under the circumstances you describe (but not when you break down the circuit into components) I would suspect a fault to ground.
You say you cut into the existing supply from the bars and this is where I would look more closely.
For example, are the connectors properly connected and insulated etc?
Maybe also confirm that it's not something silly such as the horn connector itself grounding depending on where it's mounted (like turning the steering etc.)

Chances are you've got an exposed piece of wiring or connector somewhere which is shorting and blowing your fuse...

30 amp

I have just fitted a Denali Split Soundbomb to my bike which recommends a 30 amp fuse (similar to the Stebel compressor just slightly smaller) The initial current draw to start the compressor is very high, hence the 30 amp recommendation. I have a PDM60 and have taken the 20 amp feed through a relay operated by the original horn wiring down to the compressor. Very pleased with it. (I had a Stebel Nautilus Compact for my 1150GS but it kept blowing fuses too such that I gave up on it in the end).
It is nice to have a horn that says "Excuse me, that was rather silly.......!"