Modern Vespa

I recently returned a P115W-S headlight modulator to Kisan because it would randomly stop modulating. Kisan replaced it with a P115W-AC modulator for AC systems. Their web site says:

This is a special unit for 12V AC headlights. Smaller size scooters typically have 12V AC headlights and rectified 12V DC for other lights.

Is this the correct unit for an 09 BV 250? I think I remember reading that modern scooters are 12 V DC. Will I do any damage if I install this modulator to see if it works?

Thanks for your help.
Joe

You do NOT have an AC headlight. My third, P115W-S Kisan modulator failed within 24 hours of installing it on my GTV last week and I'm still waiting for a response from Kisan regarding this problem. Your headlight (and mine) are DC powered. I have this same modulator on a GTS and a BV500 and they work fine. There's some other problem that Kisan has not yet been able to find the cause.
*Is the Kisan tech telling you to install the AC powered unit even though you have a DC powered headlight?

I just talked to Kissan tech. They are recommending that I try the P115W-AC in my 09 BV 250. They said it would not cause any damage to the modulator or scooter. I am to contact them if it doesn't work. My scooter is a real pain to take apart to get to the headlight. I'll try this to see what happens...

I installed the P115W-AC and it does not work. I expected this, but I wanted to be cooperative. I left a message with Kisan tech. They only work until 4 mountain time.

This has got me wondering if anyone has ever had a problem with a Comagination modulator. I bought one in the early spring, and haven't gotten around to installing it; I've recently been thinking that I'd leave it until next spring, since there's less and less daylight riding ahead. Now I'm worried that when I finally install it, it may be off warranty and possibly defective.

How does one tell if their Vespa uses DC current?...

If your headlight comes on when you turn the key--engine NOT running--you have DC current. The headlight for AC won't come on by merely turning the key, the engine has to be running.

I've had mine on the scooter for a couple of years now. No problems.

+1

This diagnostic falls down on newer Piaggio models - on these the headlight won't come on until the engine is running and 'happy' - typically about a three second delay. That's with DC headlights...

Jim, how new are the models you are referring to, and do you mean Piaggio in the strict sense? My 2006 LX headlight comes on as soon as the key is turned. I'm not sure if this is the same for a 2009 or 2010 Piaggio (not Vespa) scooter.

The new GTS super has an "engine happy" relay as do all the MP3s.

MP3s have the delay, as does the GP800.

I suspect (but don't know) that as new models are introduced they'll all have it. One of the big complaints has been that the headlights come on as soon as the ignition is turned on, as this doesn't help starting in 'poor conditions' (of electrical system and/or weather). It also means some tests can be done with the diagnostic unit without having to start the engine. It doesn't even need an extra relay - just a different control for it.

I'm glad you clarified that. It could be the reason the Kisan tech sent the AC version to MrScience2008, the OP. I heard the Vespa 300's headlight doesn't come on until the engine is running. Is it set up the same way as the newer Piaggio models?

I posted that two post up about the 300. 8) Mine certainly didn't come on til after the engine was running.

I'm also having problems with the modulator(s) that have been installed on my GTV.
*The headlight comes on instantly when the key is turned on and it's a 2008 GTV. My electrical system is working fine and I have had zero problems with the scooter. I also have the same model of Kisan modulator P115W-S on my wife's GTS...........no problems (the headlight on her scooter also comes on as soon as the key is turned to ON). To the best of my knowledge, the GTS and GTV have exactly the same charging systems. The only difference is that the headlight is mounted on the front fender. Kisan sent the following email today: "Some sort of a voltage spike is shorting out the voltage regulator and the microprocessor of the P115W-S unit. I have talked with our hardware engineer to see what we can do to protect the unit. We do have a Zener diode on the input for protection but the Vespa scooters may need something even more robust."
So, it appears that Kisan is taking a different approach with my problem than those experience by MrScience.................but I would think that he has the same charging system in his Piaggio that is in the GTV/GTS scooters. Kisan is following through and it's an easy task to change the modulator in the GTV, unlike MrScience who has to take a lot of plastic off just to get at the headlight. When I find out what Kisan is going to do, I'll update this thread or start another. What really has me stumped (and Kisan) is why the exact modulators are working fine on our GTS and BV500.

I installed a Comagination modulator last month and so far it works as designed. Small unit, simple to install, and works fine.

I guess it would help if I read the whole thread.

Thanks for the info.

+2

I just talked with Andy at Kisan tech. He said the specs they have on Piaggio/Vespa is that they have AC headlights, but he admits his info is a few years old and Piaggio is slow or behind on their spec notifications. He talked about a bunch of stuff I didn't understand--voltage spikes, scooters not having true alternators, whatever. He asked me to send him the AC headlight modulator so he can compare the error codes with other units that have been sent back. He acknowledged that there has been a problem when installed in Piaggio/Vespa scooters. Andy said the modulator hardware has not changed in the past few years, but the software has. Andy is working with the engineers to find a solution to the problem. Something about more protection (buffering?) from the voltage variations of the scooters. I imagine it will be a few weeks (at least) before I hear from Kisan again.

By the way, the headlights on my 09 BV 250 and 09 Fly 150 come on when you turn the key.

MrScience: I've also been dealing with Andy at Kisan. I told him a couple of weeks ago that we DO NOT have AC powered headlights on these models. I'm interested in seeing if the model that they sent to you will work on your scooter since you have a DC powered light. As I said in an earlier post, we have a GTS with the identical engine and alternator and it works fine. Every time I install one on the GTS (3 of them), they fail. The first one lasted for several days............the second one for two or three days and the last one, for only a day.

XLR8--the AC unit did not work. I am shipping it back to Kisan. Wait and see... I don't understand why the modulators work on some scooters but not on others. Can the electrical systems of the various models be that different?

That, and your history with their product, would be sufficient for me to request a refund, and then I'd go with a modulator that works on your scooter (Comagination).

Tell Kisan that the lights are directly fed from the battery via a relay, and the relay battery (duh) is charged by a three-phase alternator via a regulator. It is very unlikely (bar a faulty regulator and completely fried battery) that any significant spike will be on the raw DC feed from the battery, as it is a very good capacitor, natch.

They shouldn't use a Zener diode - how the hell can that protect itself? Muppets. They just need a 30V capable voltage regulator with a 100nF capacitor on the input for whatever voltage their electronics run at. One assumes 5V or 12V. Cheap as chips. For those who do this sort of stuff (one assumes them - unless they are really just resellers) it's not rocket science.

I read a lot of posts of people who also had trouble with Comagination, which was why I chose the Kisan modulator. It seems like you have to get lucky when you choose a headlight modulator.

I've had a Kisan P115W-S in my LX150 since April with no problems, so far.

Strange. I am always interested to read about these problems, so I'd read the threads about them. During my membership here (a bit longer than yours, I might say), I don't remember a lot of such posts as you claim. Just my observation.

windbreaker: here are some of the posts I read about comagination. Someone else complained about the lack of communication from comagination when he had a problem. I also read good and bad about Kisan.
https://modernvespa.com/forum/topic36371?highlight=comagination
https://modernvespa.com/forum/topic22603?highlight=comagination
Another Headlight Modulator Report
https://modernvespa.com/forum/topic17863?highlight=comagination

Danny: I know you have had good results with your Kisan. Your posts about the Kisan unit influenced my decision.

I'm going away for two weeks. If Kisan hasn't solved the problem by the time I get back, I'll ask for a refund and try a comagination unit.

Thanks for refreshing my memory. I remember all of those (and participated in some).
Regarding the modulation-frequency-increasing-with-speed issue, I think those are perception errors. If one looks right into a stationary bike's light, his eyes are blinded and can't follow the fluctuations. I saw mine flicker very rapidly, at 90mph, reflected in the reflectors of the car in front of me. I do concede that the frequency goes up with speed, but from a reasonable (and realistic) distance, it is visible.

Coimagination modulator did not work on my GTS 250 Super. I went through a big deal with them. They thought I had a bad alternator. I spent a lot of money researching the problem but got no-where.

The problem with the Coimagination unit was that above idle the headlight goes steady. IOW, the modulation stops at anything over about 15 mph.

I think the Vespas have noisy charging circuits. The Co-imagination guy kept telling me to get my alternator fixed while it was still under warranty.

Also the brake flasher from them stopped working after about ten minutes of riding. The only thing other than electrical, or bad unit I can think of here was maybe the exhaust heated the unit up (unit was mounted about 8 inches up into the cowl on right side).

I haven't spend the time to do a detailed search, but I don't believe that the comagination problem has been shown to affect the ET4, or LX150. Maybe it was only GTS specific.

This reply from Kisan:

Thanks for sending me the post.

Clearly whoever sent the suggestion is knowledegable in electronics.

For the record, Kisan product designs include an MOV, a Zener, a Cap and a resistor for input protection of the 30V regulator that supplies the microprocessor. Voltage spikes on motorcycles unlike cars are pretty severe. The smaller the machine, the worse they get.

Almost all alternators are 3-phase. That doesn't guaranty anything.

Anyway, I will contact you when we get the proper modifications done.

Andy
techsupport

All this tech talk is clearly above my head. Hopefully with the help of ModernVespa Kisan will fix the damn thing!

Thanks for everyone's help. I'll keep you posted.

Joe

Seeing as how 99.99% of all the ECU's out there never get fried, one hopes they'll get their circuits worked out to be a bit more robust.