Modern Buddy

So doing some work on the front end of the scooter, I decided to break out the spare Stebel and check on some mounting options. It fits very easily on either side of the tree (with the stock horn removed obviously). Working on fabricating the bracket for it.

If it's real tight in there, I'd just use some outdoor doublesided tape. That stuff holds on.

Thanks for the recommendation. Going to stick with making a bracket and possibly some heavy duty velcro as a little insurance. The single mounting bolt does not give me much confidence. Not to mention, I want to be able to remove the plastics without much problem later.

Got the bracket made. There's still a little space left over for the headlight... not much though, but it all fits. The bracket was a simple hanging plank strap that I did some work on to fabricate a slightly better fit. In all, the bracket, bolts, etc totaled about two dollars. Still need to run the wires though.

Edit: Side note, note the mounting for the blinker relocation mod. I used the same brackets and bolts to achieve the look I wanted. I did have to do quite a bit of shaving of the plastic to get it to fit properly though. Put together, it looks factory.

Wiring is complete... with the exception of a proper fuse. I did hit the horn button to make sure everything was working well though.

thats badass my friend!

Thanks! This was a fun morning project.

Okay, so I did some final checking and found whenever I had the wiring connected (regardless of keyed power), the horn was always on. So, I pulled the fuse and started troubleshooting. The diagram I went by as my base wiring was found somewhere buried deep within the MB forums for a Vespa GTS250.

So I busted out the handy tinkermeter and started figuring out voltages and ohms resistance from the physical button to the two wires where the horn leads are. I couldn't figure out for the life of me why the relay was constantly closed. So as a test, I pulled the green/yellow wire (switched ground) and attached it to the negative of the horn. I left the positive in place (orange/pink I think) and verified the switch was working correctly. Now, I wanted to make sure the decibel levels were correct with this change as hooking up without the relay the output was just shy over stock (stock 111.3db, Stebel with stock wiring 118db) that and I didn't want to blow out my horn switch over time. So the meter came back at 136db... and I was happy with that result.

So, to recap... the green/yellow wire moved from post 85 of the relay to ground/negative of the nautilus horn worked the way it should. Any other wiring junkies who may know relays better than me (doesn't take much) want to chime in to point out what I did wrong or what I could have done better... I'm all ears. I can solder like a champ, run wires like the best... but relays are and have forever been a mystery to me.

The way a relay works is that you have a low current circuit connected to a coil. When energized the coil closes a second high current circuit. Relays can be normally open, normally closed, or have both NO and NC contacts.

You would connect 12V through your horn switch then to pin 85. Your 12V ground connects to 86.

You'll see continuity between 85 and 86 because a coil is just a copper wire wound around a iron core. It looks like a short, but when voltage is applied it becomes a magnet.

When you hit the horn button you should now hear the relay click.

Connect 30 to your 12V source, 87 to your + on the horn, and ground the - side of the horn to a chassis ground.



If all the wires are the same gauge wire, then there isn't a need for a rely. If your horn button and wire are sized to support the current the horn needs, then you can just connect the horn button right to the horn. The schematic for the stock system doesn't show a relay.

I'm starting to wonder if the relay that came with the kit is faulty. When I had it wired up "correctly" the horn was always on.

You may have a normally closed relay. What numbers are on it? You should be able to google it to determine what it really is.

Good point... I'll check that when I get home tonight.

Verified the relay is the correct one, but it's faulty. Regardless of whether the switch is closed at the horn or not, the power is still being sent through 87. So will be picking up a new relay tomorrow.

Yeah, these things are cheap. You can pick them up at any auto parts store. They fuse shut pretty easy. If you buy one rated higher than the amperage of the horn it will last longer.