Modern Vespa

The security alarm connector behind the left knee panel of most GTS250's has all kinds of electrical goodness to be tapped into: power to the left and right turn signals, 12 volts upstream of the key switch, 12 volts downstream of the key switch, and ground. These two 12 volt sources either side of the key are fused at 10 amps each, and both of those 10 amp circuits feed only the instrument cluster - and a security alarm, if you have one. If (like me) you don't, you've got plenty of juice available right there.

As luck would have it, two very useful but simple electrical mods - a turn signal beeper and an accessory power outlet - can get everything they need right there at the alarm connector. And the knee panel is just the place to mount them. This project, then, is actually these two mods in one.

I try to mod my scoot with as light a hand as possible:
* The mod does not overload or otherwise compromise the circuits it is tied in to.
* Factory wiring is not cut, spliced, or otherwise altered.
* Only easily replaceable scooter parts are cut.
* All added components and wiring are mounted and connected so as to withstand the vibration and dirt inherent in road service.
* The finished install is visually clean and compact, both inside and out.

I used the following parts. I got all my electrical parts from Radio Shack, so I'm including the Radio Shack part numbers (with links) and prices:

Piezo Buzzer, 273-068, $9.49
Accessory Power Outlet, 270-1556, $6.99
6-position Barrier Terminal Strip, 274-659, $2.39
1N4005 Diodes, 276-1104, $0.99 (for two)

1N4005 diodes are actually overkill for this application, but they're cheap, available, physically small, and they work fine. They'll take an inverse voltage of 600V (they'll only see 12V here), and they'll pass 1 amp (the buzzer only draws 10 mA.)

I also used:

6-32x½" machine screws (qty 4, for mounting the terminal strip)
#6 lockwashers (qty 4, also for the terminal strip)
6-32 nuts (qty 4, ditto)
#16 stranded wire (a few feet, included with the power outlet)
small wire ties (qty 4)
spade-type crimp terminals (qty 8.)

Crimp terminals are great for connecting stranded wire to screw terminals without the stray wire strands or loose mechanical connections you get when clamping stranded wire directly under screw heads.

Altogether, these materials totaled under $25. But, because I'd be cutting holes in the left knee panel, (and taking the "keep it factory" constraint to the extreme) I also ordered a new panel from Piaggio through my dealer. The part number is 577395000C. As I remember, that part cost something like $30. It's optional.

I tapped into the unswitched 12V for outlet power because I wanted to be able to connect a battery tender to the battery through the outlet while the scooter is parked and turned off. You could just as easily tap into the switched power if you want the outlet to be hot only when the scooter is on. The choice is yours.

All s appreciated.


Here's a sketch of the mod.

On the knee panel, mark the centers of the holes for the outlet and the buzzer, 1½ inch from each side, 1½ inch from the bottom.

Cut the two holes in the knee panel with a 1 inch hole saw.

Open both holes up to about 1-3/16 inch with an abrasive drum. I used a Dremel tool attachment.

Work slowly and trial fit as you go. You don't want to make these holes too big!

De-burr the finished holes with a sharp hobby knife.

Cut a small square clocking notch on the left side of the outlet hole. Use the rib on the outlet housing as a guide.

Mark the centers of the terminal strip mounting holes, using the terminal strip as a template.

Drill out the terminal strip mounting holes with a #28 drill bit.

Mount the buzzer, outlet, and terminal strip to the knee panel. The terminal strip mounts with the 6-32 hardware.

Mount the diodes "bands together."

Wire the components to the terminal strip per the sketch above. Use crimp terminals at the screw connections.

Tap into the alarm connector as shown on the sketch. Stranded wire works best here if it's first tinned with solder and slightly mashed.

Secure the wires to the plug and to the plug harness with wire ties. Return the harness to its clip behind the knee panel.

Secure the knee panel to the leg shield. Black screws would really make it look finished.


Last edited by Cincinnati John on Sat, 10 Oct 2009 22:49:48 +0000; edited 12 times

Very well thought out and nicely documented. I think even I can follow what you did. Yes, you need black screws for the terminal strip.

Any reason why you couldn't mount the terminal strip inside the cavity of the left knee pad? Looking inside mine, it looks like some type of small bracket could be made to be attached semi-permanently. Looks like there are two unused placed where a bolt could be screwed in. Plenty of room inside for all types of "stuff".

Please report back on two things. 1.) how the Battery Tender Jr. works with your setup, and, 2.) if you can hear your beeper when you are driving, (do you have a fly screen or some such?)

Thanks Steve - I appreciate that.

There's no reason at all the terminal strip couldn't be mounted in the cavity behind the knee panel. The only reason I put it on the panel itself was so I'd only be cutting holes in a replaceable part. As it is, I can pull the wires out of the alarm connector, remove the modded knee panel, install the original panel, and I'm back to stock without a trace.

The battery tender works great with this setup. Just plug the output of the tender into the power outlet. Couldn't be easier or cleaner.

The beeper's tone is 2.9kHz at 80dB - fairly piercing. It's clearly audible, even at highway speeds. (I don't have a wind screen.) As a matter of fact, I worried at first that I was annoying the cagers at traffic lights, but I finally decided that anything that attracts attention is good. I used to have a beeper installed behind the horn cover. It was loud enough to be heard when stopped - but not when moving, and that's when you really need it. This is much better.

Last edited by Cincinnati John on Thu, 28 Aug 2008 12:12:25 +0000; edited 1 time

Thanks John. One last question...how do you think the buzzer will hold up to the weather? The outlet has a cover, but not the buzzer. Any concerns about rain or mist?

The buzzer element is recessed pretty far into the housing, and is covered over by a thin plastic membrane. As I have the buzzer mounted, it's angled downward slightly, so any water that got inside would tend to run out. That said, the buzzer is not advertised to be weatherproof, so I wouldn't count on it surviving repeated soakings. But looking at it, I don't think occasional light moisture would hurt it. I can't see mist being any problem at all. Parking outside with no cover might be a problem after a while.

EDIT: I just now took another look at the back of the buzzer's bubblepack card. It says the buzzer is waterproof.

Last edited by Cincinnati John on Mon, 18 Aug 2008 15:18:04 +0000; edited 1 time

Perfect! Stopping at Radio Shack on the way home tonight...and after printing out your excellent directions.

Great project. Very succinctly done. I might have to do that one myself. I have 2 buzzers plugged into the connector right now placed near the side vents. I can hear them at speed.

Maybe some Testor's black model paint might work on the exposed screws?

I wonder if Piaggio or some other manufacturer makes the mate to that connector that you could build a harness from?

I also have to think of a use for the switched jack as well, heh!

Wow, that really is all neat and tidy, very well done!

Thanks! I thought about painting those screw heads. But I'd probably wind up eventually replacing 'em with black oxide screws anyway. They're out there; I'll find 'em. EDIT: Found 'em at Fastenal, cheap. They'll be here tomorrow.

I would love to find the mating connector somewhere. I'd buy five copies. That would really clean it up.

Just for the sake of completeness, here's a sketch of the alarm connector with pin assignments. View is face-on:







Last edited by Cincinnati John on Wed, 30 Sep 2009 22:07:52 +0000; edited 4 times

Thanks for this John. Most helpful to see the wiring of the alarm connector!

You're a star!

(The blue and black wire leads to an unused connector under the seat to operate a push button foor the alarm system. This pushbutton connects to a red and blue always positive wire and the blue/black wire, delivering 12v +ve to the alarm system when the seat is opened.)

Checkout - Turn Sig's Revisited - 23 December, 2006 - by carrelro.

I did his mod and it works very well and was simple to do.

John, received my Battery Tender Junior last night, and there was not a cigarette lighter plug enclosed. Is this something you spliced into your Tender, or did your's come with a lighter plug?

Steve, digging into memory a little here. The battery tender output cord has one of those polarized "yin-yang" connectors on it. I left that in place. I made up an adaptor cable by connecting a lighter plug to one of the accessory cables that came with the battey tender. I'll take a photo tonight and post it.

Thanks John. No need for a photo. I can jury-rig something. I'll use the alligator clip cable, cut off the clips, and solder on a plug. Was just wondering if a d/c plug was included with the Battery Tender or not. Is the nipple of the plug positive or negative? Positive, I think.

---

edited to add: Never mind. Your first wiring diagram shows the nipple as positive, just a s I thought.

Steve, What you're describing will work fine of course and is exactly what I seem to remember doing. But looking now at the actual adaptor, it sure looks like it was commercially made. I have no idea where I got it. Must be having a Senior Moment...
I've got the photo right here, so I may as well upload it in case anybody else wants to see it. BTW, I just metered it out to be sure: the exposed pin on the "yin-yang" connector is negative. And yes, that center contact of the lighter plug is positive.

...black screws.


I feel better now.

Looks much better, John. You know, I was worried about the "amateurish" look of exposed screw heads, but when I went for a ride to the market last night, I was looking at the kneepad in an attempt to determine where to put a push button for my garage door opener and a blinking LED for an alarm. I discovered that the top part of the kneepad is pretty much hidden under the handlebar, and isn't very noticeable.

Steve, the screws may not be visible while you're in the seat, but still you'll want it to look good from the side when its parked. As you'd mentioned earlier, the terminal strip could also go back there in the cavity behind the knee panel. Also, I hadn't tried epoxy to see if it would grip to the back of the panel, but that might be another option.
Funny thing your next mod is going to be a pushbutton for the garage door opener. I'm headed that way myself. Wouldn't mind seeing a photo of your job when you have it done.

I just want to add another "Excellent Article" comment. Stuff like this makes the forum a must read.

Thanks for the detail I will use this to possibly attach my stereo... if it ever comes.

Black screws. Snazzy.

I bet if you threw a few of those together and made a "knuckle head proof" easy way of connecting to the plug you could probably make some extra "modification" income.

This is an Excellent mod. Thanks John.

I'm going to shopping at Radio Shack this afternoon.

Same here, its go me really wanting to attempt that project this weekend. It very detailed & helpful, especially to the ones (like me) who are not very electrically inclined. Thanks John

The thought has crossed my mind. Connectors...need connectors... Thanks! Glad you made your first post here. Welcome to MV!

Battery Tender cigarette lighter adapter
http://www.scooterworks.com/Battery_Tender_Cigarette_Light_P5478.cfm

That's the ticket. You'd pay $6.95 for the whole adaptor as opposed to $5.99 just for the plug.

Great job on this mod John. Your instructions were spot on. I just completed it on my GT200L. It works great. Thanks for the great job and instructions.

PS. How is the horn button hoding up with the new horn?

Thanks - glad it worked our for you!(pictures? )
Horn button is holding up fine so far, but my immobilizer antenna went south about two weeks ago and I'm still waiting for a new part. But no sign of trouble after about four weeks of riding.

here are a couple of pics John. There not to great I'm not much of a PO-tographer...lol

The only thing that I did different form you was to epoxy the terminal strip into place in leu of using screws it seems to work great.

I was thinking today about what I would do if I decided to install an alarm. I hate to splice !!!

Thanks again for the great info... David


Front Shot

Inside

Clean.
It does look better without the screws.

European tenders are very nicely designed w included cig . plug ..And their cig.sockets are really nice . Would seemingly look nicer on a European bike.Good mod though

Hi Guys. That stuff looks GREAT!!! But, I'm a little nervous about what might happen to the instrument cluster since the wiring diagram looked like the alarm wiring ties back into it. So, I'm adding a little bit of a different approach. Instead of the Piezo buzzer I went and got a couple of Bosch Relays and an LED Flex Strip. I'm going to mount the Relays under the knee pads so it will click like cars do (hopefully it is loud enough) and use that 12v to signal the relays to switch them on and off. I've had some relays in the past that were loud and some that were quiet but I'll let you know. I also bought a Euro Style terminal strip instead of the Barrier Terminal Strip. It was 12 position a bit more compact and I could cut it to use other terminals elsewhere for 20 cents more but I didn't have to get any crimp spades.

The LED Flex Strip came with 26 LEDs that you can cut appart. I plan on putting some under the lenses in my top case and some under the side markers so they flash opposite my normal signal lights. I'll be posting pics and will let you know how loud the clicks from the relays sound along with details depending on how good it turns out.

This will probably end up being a little more expensive but it will allow me to tie in some LED signal lights along with the signal sounds and I know the load through the alarm wiring won't change as I do more stuff.

No risk to the instrument cluster here. The cluster supplies pulsed 12V to the turn signals. The alarm connector is in parallel with the turn signals, so that the signals flash when the alarm goes off. So, since the pulsed 12V also appears at the connector, I'm just picking it off there. The piezo buzzer draws miniscule current, on the order of 10 milliamps. The coil of a small relay will draw a good deal more than that (more on the order of 100 milliamps), but is still a safe load on the turn signals; heavier relays will generally draw more current. For comparison: the turn signal lamps are 10 watts each, or 20 watts per side; 20 watts ÷ 12 volts = 1.7 amps.

Okay, I totally buy your explanation on how the cluster is pretty much safe. The relays are way too quiet anyhow. I'm still going to use them for my side markers and the lights on the top case though.

No pics yet. I'll do it all in 1 post.

Thanks.

I wish I was as handy as the rest of you seem to be on this thread. I will have to resort to having my local Vespa dealer install these mods. I will be bringing the diagrams posted here to make sure they know what they are doing.

Thx a bunch

Great jobs to everyone who contributed

G

Great Project Report

If you want a volume control on the Piezo Buzzer try this one.
I have installed on my ET4 and GTS with great success using this same design.

I am running at about 1/2 volume setting and not driving other drivers nuts.

Cost is $3.95 at All Electronics. Link is below.

http://www.allelectronics.com/make-a-store/item/SBZ-365/4-28-VDC-PIEZO-BEEPER-W/VOLUME-CONTROL/-/1.html







Last edited by ExonicJay on Sun, 18 Jan 2009 05:11:56 +0000; edited 1 time

Nice Job 8) 8) 8) What are all the little toggle switchers for please on the knee pad

Switch #1 = Oil Slick
Switch #2 = Reverse Thursters
Switch #3 = Smoke & tacks

The Right knee panel has the real goodies.
But I can't tell you or Q at MI6 will be pissed.

Just kidding.

Three switches are for garage door openers
One Switch is for the Headlight Modulator
1 LED for alarm (Gorilla with remote pager)
And of course a cigar lighter also used as a charging port for the battery.
And the piezo beeper for the turn signals.

Picture shows battery tender plug connected



The the Right knee panel really does have MI-6 stuff.
Only Q and 007 know what it does.

I have now labeled some of the MI-6 functions on my ET4.



Here is where to by the labels:
http://www.aestheticreations.net/smartgroupbuy.htm

Last edited by ExonicJay on Sun, 09 Nov 2008 05:05:23 +0000; edited 1 time