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Discussion Starter #1
Hi,

My ST2 stopped charging the battery, and reading the threads I found that the regulator is the likely cause. Also looking at the threads and parts available, it appears that 99 and later bikes have different regulators than the early ones. The late ones are $25 on ebay even though ebay says they go from '97 up. Mine has the 4 big wires, yellow, yellow, red, black, and the two small black and white wires. The few I see on the net are $300+.

My question is can I use the later, less expensive one on my bike, if so how do the wires match up? Any other suggestions?

thanks, Matt
 

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97 is unique, no other ducati ever used it.

yes, use a later one. just ignore one of the 3 yellows and the black/white. put it in the air duct like the later bikes. run the red and black direct to battery with fuse in red. i go via the oem maxi fuse, but i have terminals to use them.

it probably is the reg, actually amazing an original is still there. but before you replace the reg on internet suspicion, DIAGNOSE THE FUCKING THING.

sorry, it just gets to me, the "it stopped, so i just replaced everything and it still won't work" mindset.
 

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You can use the newer VRR. You would just not use one of the yellow wires on the new regulator. You will also loose the red charge fault light on the gauge cluster.

A common mod is to ditch the older style diode regulators and go for a newer style, cooler running and more reliable, MOSFET regulator. I've done that to the 916 (also a single phase bike like your ST2) and the ST4s. It has worked out perfectly on both bikes.

There is more to the story though. You also need to have a look at the two yellow wires going back to the generator to be sure there is no evidence of heating. Many have replaced those wires with a higher gauge. I used 10 gauge on the 916 and left the ST4s original.

This link discusses changing the regulator. It references a seller that provides kits. I looked to eBay for the regulator. You can find them listed for 07, 08 Yamaha R1 and others for around $40 used. The regulator I've used is the Shindengen FH012AA. I purchased the needed plug kit from this guy: Home and made my own harness. He sells whole kits too, but I'm too cheap to do that!

http://www.ducati.ms/forums/80-hall-wisdom/94947-upgrade-fix-no-more-charging-regulator-rectifier-problems.html

If buying on eBay, beware of regulators that are listed as new for around $50.00 and look like the MOSFET units. They are knock-off crap. A new genuine unit is $120 or so, clean used ones should be in the $40.00 range.
 
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I replaced the RR on my 1997 ST2. I used this exact plugin, so the charge light on the dashboard works correctly. I cut the connector for the yellow wires off and soldered on automotive push fit connectors. That I then soldered together for good measure.



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Similar to SS904 above (being a cheap bastid !!), I opted to use a $30 used RR that I carried as a spare for my 1998 ST2. Of course, Murphy allowed my OEM RR to run flawlessly for 53K miles, so I never used it for the older "97 and 98" ST2.

But I have a 2002 MG Lemans that would not product over 12.5V on the battery, above idle. So I scabbed this RR into the Lemans, which is a single-phase, 350W stator. That said, I did diagnose the stator first, including a load test with maybe 100W on just the AC voltage output. After being satisfied that the stator was healthy, I installed it as SS904 described above. It works great, although you lose the alternator light function (black & white wires).

If this function is important to you, then you'll spend a lot more on the one that RedSquare described.
 
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Discussion Starter #9
Thanks all for the advice. I did check the part using the resistance method described in a post. There was infinite resistance between the red and one of the yellows.

So does it matter which of the yellows I do not connect to the alternator?

thanks, Matt
 

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