Modern Vespa

Last month I installed a Kisan head light modulator on my BV 250. The modulator would work for a while, then stop working, then start again. I could not determine a pattern of when it would work and when it wouldn't. I contacted Kisan and sent the unit back to them. Yesterday I got this response from them:
We have the unit on the test bench for last two days. No errors
have shown up but the Error Codes in the memory of the unit
indicated input voltage failure.

Anyone know what this means? A problem caused by my scooter? Voltage regulator? They are sending me a new unit, so I'll see if the new modulator works correctly.

I'd be interested to hear what you find out. When do you have issues with yours?

For me, the modulator works fine during the day. However, a small percentage of the time at night, I'll flip the high beams on and get a blinking headlight instead of steady. Very annoying!

My modulator would just stop and start randomly. Sometimes turning the high beams off then on again would start the modulator working, other times that would not work. The modulator would stop working on shady streets or sunny streets. Turning the scooter off and restarting it might start the modulator working, but not always.

If your head lights modulate at night is it possible the light sensor is picking up light from other vehicles? The light sensor is supposed to be pointing up. If you are driving down a brightly lit street, maybe the light sensor is picking up the light from street lights. You could cover the light sensor with a peice of tape at night to prevent the headlight from flashing.

Mine doesn't pick up the street lamps. I wonder if the sensor is pointing forward enough to catch on-coming headlight beams.

Covering it up and seeing if the modulation continues would seem to be a simple test.

I bought three Kisan P115W-S model modulators about 5-6 weeks ago and two of them have failed. Both of the units that failed would work and then stop working with no flashing but the headlight would stay on bright.......then the bright light would not work at all. The first one was replaced by Kisan bout four weeks ago and the replacement has worked fine since then. The second one failed about two weeks ago and the replacement arrived today. The man that I have been dealing with sent this message re. the first unit that failed: "I looked at the comments noted by our tech's on the unit you returned. And it says that the high-frequency trap of the unit was activated. (Error Code 0Xh8) They were able to reprogram the unit. So there was no hardware damage. However, the Mfg Date code was from 2006, so it was thrown in the junk pile."


So, I don't know exactly what that means since I'm not an electronic tech but the mfg. in 2006 may just possibly mean that there have been some updates to their software since 2006 the modulator that was replaced last month is brand new and is working fine. Kisan has been good about replacing both defective units but they are "slow to ship" the replacements. At first, the rep from Kisan thought that I might have an AC powered headlight but I assured him that these were newer scooters with DC powered lights. They are looking into what may have caused the problems.

I gave up on modulators, my first Kisan failed, no modulation, no high beam. The replacement modulated wonderfully, but the low beam didn't work.

Returned for refund.

Tried a comagination, it failed to modulate at any speed over idle.

Returned , and I threw in the towel

I feel lucky, my Kisan has worked fine since day one. I have an LX 150, I wonder if that has anything to do with it. Simpler electronics?