Regulator

[willembop]

I've had cold starting problems with my 2007 Xciting 500. Here's what I most recently did. My regulator/rectifier only put a maximum of 13.2 volts to the battery. Type of battery didn't matter, new, old, or even lithium. Charge voltage didn't rise above 13.2v. The stator output is fine, about 25vac across each phase at idle, 60vac when revved. In my experience on other scooters and motorcycles, the voltage at the battery should rise up to the low 14s, usually about 14.5, when the battery is fully charged. So I got a new replacement Kymco regulator, and it behaved identically, i.e. not more than 13.2 volts. I saw some discussion about replacing Kymco regulators with an old Honda regulator that is a Shindengen 232-12 (used on CM400 and CX500 models, and maybe others). I got one from Ebay for $12 including shipping. The Shindengen regulator is a 6-wire unit, while the Kymco is a 5-wire, and the 6th wire (the black wire) needs to be connected to a switched 12-volt source. The Honda regulator has different electrical connectors. I cut them off and used the connectors from my replacement Kymco unit, soldering them to the Shindengen wires (same color wire: 3 yellow, 1 red, 1 green), so I wouldn't have to alter the stock wire harness. The black wire I spliced into the brown wire of the hazard unit, which is right next to the rectifier. (The brown wire provides 12v to the tail lights.) I used a bullet connector on the black wire, so I can unplug and remove the new rectifier if it should become necessary. The new regulator works great and gets the charging voltage up where it should be. Voltage at the battery is 13.5v at idle, rising to 13.9v in a couple of minutes as the engine warms, and I expect it will rise above 14 after a while, though I haven't road tested yet to see. I'm pretty sure this will give the battery a little more oomph when it's cold, although I'll have to wait for next winter to find out. I should mention, in case anyone is interested, the mounting holes of the Honda unit are slightly further apart than the Kymco, but the aluminum case is pretty soft and easy to modify. I notched out the material inside the bottom mounting hole, using my band saw, until I could get the top hole lined up and secured it with just one nut on top, which seems to be plenty.

[CROSSBOLT]

That is confirmation! The only thing is the Shindengen should been EXACTLY like the Kymco. Wire colors and connectors. The regulator is used in many different vehicles and your genius has adapted to work in yours! Outstanding!

How and where did you get the info to hook the black wire to 12 volts? I will bet you figured it out by yourself! How'd you do that?

I have done more studying the 232-12 and Shindengen in general. The regulator Kymco uses is called a "shorting" type which grounds the alternator to regulate output! Shorts it out! They have another type which gates the output with a MOSFET semiconductor ( my eyes are glazing over!). I cannot tell which the 232-12 is but it has a better track record than the Kymco part and in your case, improvement that is measureable! The stator failures may be explained by the Chinese made Kymco part! I will post in a separate thread when I learn something new.

[xsel777]

I was told recently that the regulator on my xc500 is also not going high enough. Which honda model has the same fitting as the kymco?

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[willembop]

I would like to find a plug-in replacement for the Kymco regulator, but a lengthy survey online failed to reveal a plug-compatible unit. There aren't many 5-wire regulators in use like the Kymco, but the regulator for the 2008 Honda SH300 seems to be one. Of course, the connectors would not work, but you wouldn't have to splice the black wire as I did. I don't know the dimensions between the mounting holes of the SH300 regulator, so I don't know how easily it would fit on the mounting studs. BTW there are a lot of 7-wire units around, i.e., 3-yellow, 2 red, and 2-green wires (no black wire). They would also work, because the double green and red are connected together inside the unit. You could just cut off one red and one green, or, better yet, tie each pair together.

[xsel777]

If I went this route, I would do exactly what you did, because I know zero about these things, but can follow instructions, and am quite handy with hand tools. If I may ask, to reassure myself, how do you know that these 7 wire one's are really 5 wire ones with the dual wires of same color.? I am starting to get the impression that these regulator rectifier combo units all function the same way, it is just a matter of the wires, and connectors.

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[willembop]

About the dual wires being really one? It's just the wiring design conventions that engineers (usually) follow. Red is most always the hot side of the battery and green is ground. If you look at the schematics for any of those regulators with a double wire output, like a VF700C for example, both of the same colored wires end up hooked together upstream. This is done to provide increased current capacity. They could have used a fatter wire instead, but the two thinner wires are more flexible and easier to group in a harness.

[willembop]

I should also note to avoid confusion that the VF700C regulator that I referred to as an example is actually an 8-wire unit. Two green, two red, three yellow, and one black wire. Which is essentially the same as those with 6 wires, just the red and green doubled up. To summarize, the three yellow wires are the AC input to the regulator from the stator. If there are only two yellow wires, that would be a single phase regulator, not compatible with the Xciting 500. The red and green wires are the DC output that charges the battery. And if there is an additional black wire (usually known as the "sensing" wire), it is connected to a switched DC source, which effectively turns the regulator on and off when the ignition key is switched on and off.

[willembop]

One more note on the function of these regulators. The ones with the black sensing wire are internally different from those without. The ones without the black sensing wire don't need an on/off signal to operate, and they act like an open circuit automatically when their output is less than the battery voltage. So they won't drain the battery when the scooter is not running. The ones with the black wire need the electrical signal to switch them off, otherwise they would drain the battery. So internally there are two distinct types of regulator circuits. The other variable is the capacity rating, i.e., how much current the regulator can supply. This is not shown on the regulators and is not listed in their specifications as far as I can see, but you can get a general seat-of-the-pants estimate by comparing the physical size of the regulator and its heat sink/fins, and also the thickness of its connecting wires. If the wires are thin, they cannot carry much current, while thick wires mean a lot of current capacity. Also, and this is just a guess, I noticed that most manufacturers, and particularly Honda, employ the regulators with the black sensing wire, so I think that is the superior setup.

[CROSSBOLT]

I cannot say for sure, that is, I lack proof but the Honda part is generally the best especially electrical. I have been unable to verify which regulator is the open type. To recap, shorting regulators actually short the output of the stator to stabilize the system voltage and charge the battery properly while the open (think this is the right term) type vary the current with solid state electronics so the stator is not 100% loaded all the time. The Kymco have the shorting type and I suspect they are china-made.

[xsel777]

Great guys, I will pop into the local motorcycle graveyard and see what I can lay my hands on. Although I don't need it right now, but winter is coming, so I might be proven wrong as my battery is beginning to get tired.

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[szabgab]

Hi,  sorry to bring an old thread back to life,  but did you guys find a direct replacement? Also the name/type is written on the Honda regulators? Only because I can get to a local salvage yard,  but I would have to know,  what I'm looking for

[szabgab]

Hi,  sorry to bring an old thread back to life,  but did you guys find a direct replacement? Also the name/type is written on the Honda regulators? Only because I can get to a local salvage yard,  but I would have to know,  what I'm looking for

OK, nobody replied, so I was today around the yard and bought an SH232-12, it is actually the same, that was mounted on my old Honda cb400 and which worked perfectly.

Which brown cable willembop did you split? Also, if the hazard unit is the one, that is supplied by the wire, is it an ACC source? If I can\t find the brown wire, I might split the charger cable, but which one? Positive or negative cable (I guess it makes more sense to connect to the hot positive wire, but you never know)?

Thanks!

Gab

[CROSSBOLT]

That is great news, Gab, that you found the Shin in a yard! I think the brown wire can be found going to the tail light which I am assuming is near where the reg-rect is located. I guess I am also assuming the tail light also comes on with the ignition!

[szabgab]

That is great news, Gab, that you found the Shin in a yard! I think the brown wire can be found going to the tail light which I am assuming is near where the reg-rect is located. I guess I am also assuming the tail light also comes on with the ignition!

Karl, I think US legislature requires the bikes to have the lights on all the time, so they are probably connected on an ACC line, not here though, I'm afraid. But again, I might completely wrong, and the brown wire is always hot, if the key is inserted, I will have to investigate. But where is that sodding brown wire? I might just trace it back to the blinker, or the clicker of the hazard lights, as one can turn on the hazards, as long as the key is in the ignition

[szabgab]

BTW, the 232 was not very cheap, it cost me around 25$, but this is the same price, an aftermarket reg-rec would have costed, so I thought, if you guys think, the Shin is better than a shorting type, I will get this. Also the Honda's charging system was bulletproof and my old bike started no matter the weather, so I would not mind that surety transplanted into my new bike