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Videos: Headlight brightens and dimms-charging system test

1495 Views 22 Replies 4 Participants Last post by  zugre
Hey can someone help me, i had an issue with my headlight?

Headlight randomly brightens and dimms. You can see on the video i took…

At iddle, it dimms and if i rev, it brightens. But also brightens and dimms randomly (not only if i rev), you can see that also on the video.

When im driving i.e. at 4 gear at constant 4k rpm, it randomly dimms and then brightens again all the time and its so annoying for those in front of me…( like i am blinking with long light)

This is happening only when the bike is warm. (At least 70-75c). It is working normaly on start till bike warms up, then the issue appears.

Maybe the problem would be a faulty regulator / rectifier ?! I want to be sure and then buy the new reg rect. Any idea how to test and inspect? Maybe battery check at constant rpms?
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+1 on a voltmeter. You could start at the battery terminal but I'd like to see something further downstream. Try connecting it to the O/G lead on your dealer mode connector. There's a B/W ground there too. It seems to brighten considerably when revved at first but later stay constant. That may be a voltage regulation issue.
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+1 on way too high. 17.7 V sounds high enough to put the ECM at risk. It could also hurt your battery.

It's not a big deal but I'd prefer that you use the 20 V range as it might reveal some unsteadiness that's not seen on the 200 V range.

It does sound like your R/R isn't doing its job. The service manual has a bunch of diode tests to do on the R/R. You might as well also inspect the stator's voltage and resistances. You'll need the 200 V range for the voltages.

FYI, incandescent bulb brightness goes up by V^3.5 and life goes down by V^12. So going from 14 V to 17 V doubles the brightness, which we see in your videos, and decreases the life by a factor of 10.

P.S. Is that an aftermarket seat?
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It's probably OK but you didn't check the stator resistance to ground. It should be high.

The diode tests check the R/R diodes but not the voltage regulator. I continue to suspect it as the R/R has already failed the voltage tests. You might be right about it acting up when it gets hot. The underside of the R/R is potted in a black epoxy compound. Do you seen any evidence of damage to it that might be associated with local overheating?

The brown in the seat goes well with the black bike. Whoever did that knew what they were doing.
"there was default ‘0L’ on multimeter display. Are you meaning to this?"
Yes OL is a high/infinite resistance, which is what it should be.

I think your R/R should be 32800-47H00. I'm used to the black epoxy on the underside but after looking at several on ebay (lots of mislabeled parts there), I now believe that yours should look like this. The eighth image shows the underside as a metal plate. This is new to me. But you can see that it's a Shimaden SH811AA.

Per the service manual, the voltage regulator test is the regulated voltage inspection that you performed above, and which failed.

I personally don't have a problem with your battery but opinions vary. The only thing that I'd avoid is a cheap battery from China.

P.S. Search for "What are the symptoms of a failing voltage regulator?" Note too high a voltage and dimming/pulsing lights.
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I agree that it must be the R/R.

It doesn't matter for you but it appears that the units with black epoxy on the underside were made by Kokusan Denki (RS41), now part of Mahle, and the ones with the stainless plate were made by Shindengen (SH811AA). I can't tell but wonder if Kokusan Denki got out of the R/R business and Suzuki switched to Shindengen. The Shindengen FH20AA is a superior MOSFET type but you have to deal with the connectors and mounting hole spacing. This indicates that there are some complications with testing a newer type R/R. It's tough to tell what you're getting with an off brand R/R, for example this and this.
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You can buy a new 32800-47H00 for about $200 and be done with it. You can buy a used 32800-47H00 on ebay for $50-$60 but you have to be careful there as many are mislabeled. The real ones are stamped 47H00 and SH811AA and have the stainless plate on the underside. Also, unlike the earlier Kokusan Denki R/Rs, the heatsink fins don't have circular risers or ejector lands (or whatever they're called) on them.

MOSFET I think of them as low resistance transistorized switches but may be somewhat off base there.

You can buy a Shindengen FH020AA here for $100+. The real ones are stamped with the Shindengen logo and FH020AA and the stainless plate isn't held on by screws. The cheap ones there are highly suspect. Ironically the $26 AliExpress R/R that I link to above has the right markings & plate. You could try asking him if it's a real Shindengen.

The FH020AA has 70 mm mounting centers vs 80 mm on the Suzuki so you'd have to deal with that. It might be as simple as elongating the holes in the R/R or maybe those on the bracket that supports it. You'll also have to make adapter connectors. The GHC R/R linked above supposedly has extended mounting holes. They're in Taiwan instead of mainland China and seem more believable. But I can't find any specs or distributors.

P.S. I don't claim to be knowledgeable about this but think that Yamaha started using the Shindengen FH012AA around 2006. It was later replaced by the FH020AA. I don't know why Suzuki hangs onto the older technology as, per the Wikipedia article, MOSFET technology is definitely superior.

P.P.S. The ebay seller of the FH020AA says the plate is stainless. But here's a Shindengen data sheet for the FH012AA that says it's aluminum. I don't know why the later part should be different.
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