bike acting funny (battery/charging problem)

[Howie]

ok, got the battery charged up, installed it, HOWEVER, this time when i connected the negative terminal, there were no sparks  so i didn't bother pulling out all the fuses, should i do it anyway? what i did was run the bike at about 3000-4000 rpms and checked it with the multimeter but the voltage remained. it didn't even budge. so i figure could this be the alternator. i unplugged the socket, ran the bike again, and checked it with the multimeter (AC current) all 3 leads were within spec. could this be the rectifier/regulator then? did a search on the forum but can't seem to be able to find anything on checking the rectifier/. howie???

thanks

Maybe the sparks were from the immobilizer trying to do it's job, not sure.  If your multimeter has a milliamp scale, check for a draw anyway.

Here is a great guide:
http://www.electrosport.com/technical-resources/library/diagnosis/fault-finding-guide.php

Sounds like a regulator, but before condemning it make sure all connections are good, particularly where the stator plugs into the regulator.  Also make sure the regulator is well grounded.

[Fruity]

thanks for the link howie, the guide lost me on page one. i couldn't find the black wire coming out of the R/R and the chart only specified Jap bikes, plus it was getting dark as well. there are 7 wires coming out of the R/R; 2 color in pairs and a single color with 3 wires. can't remember them exactly but definitely no black. any ideas?

thanks

[Capo]

The three large yellow wires will be the AC output from the alternator, the other pairs are DC + & -

[Fruity]

thanks very much capo. so i assume i have to test both set of wires, the red and brown to see which is negative. the other 3 wires are brown and if they're supposed to be yellow, screw me then they're probably burnt. then that's where my problem lies.

[ducpainter]

thanks very much capo. so i assume i have to test both set of wires, the red and brown to see which is negative. the other 3 wires are brown and if they're supposed to be yellow, screw me then they're probably burnt. then that's where my problem lies.

Are they brown on both sides of the connector?

All Duc alt wires are yellow.

[Howie]

Besides the three yellow (stator) wires you should have a pair of red wires which are positive and two black wires.  The black wires are ground.  Pay attention to the bike side of the connector, not the regulator side since your regulator may be an aftermarket unit.

[Capo]

This is the regulator from a 04 S4R. Note that the two 'black' wires are in fact green (they must have run out of black that day  ) the wiring diagram refers to them as being black.

The pair of red wires go to the 40A fuse which is located on the left hand side of the battery mount.

[erkishhorde]

That looks exactly like the regulator they sent me when mine blew up on my m900.

[Fruity]

thanks for that picture (picture says a thousand words) so there's been discoloration of the wires on my bike. so i'll got test it now. my gut feeling is the rectifier/regulator is kaput. are all RR the same for the bikes? (superbike 748,916,996,998 series and the 749,999, all monsters , STs, Multis etc) thinking of getting one off ebay. thanks

[ducpainter]

There are single phase and 3 phase alts and rectifiers to match.

There are also some differences along the way in the single and 3 phase.

[Howie]

Chris Kelley will sell you an Electrex brand new replacement  for $109 minus your DMF member discount.

http://www.ca-cycleworks.com/shop/catalog/ducati/elec.html

Scroll down.

[Fruity]

thanks for the link howie. now the question is do i buy a brand new one or a used one off ebay. there's a couple floating on ebay that's relatively cheap the came off 2003 and 2006 bikes. what's the life on a rectifier? then again it's ducati electrics, right

[Capo]

Check your system first.
Do you have a shop manual?

[Desmo Demon]

Check your system first.

Do you have a shp manual?

+10,000.....you need to make sure which component of the system is bad before you go changing parts....costly parts. If you want to check the system, definitely buy a repair manual. They describe ways to check each component of the charging system.

You are correct in checking for 13.0+ volts DC across the battery terminals with the bike running at 2000+ rpm. You haven't told us if it is still showing a charge after getting it back home. Charge the battery and check the voltage regulator output. If it still looks good, then you potentially have a bad battery or the stator can be dropping out at even higher rpms (I've seen them do this before). If it still shows that the regulator is charging, I usually buy a cheap $10 voltmeter at an auto parts store and temporarily install it, then drive around and check the voltage readings at different rpms. If it is charging, but not keeping up with the demands of the system, you have to find out where the drain is. The first thing I would do is dissconnect the headlight plug and check the system, again. I am suspecting an overload on the system if your yellow wires are brownish. This means that the system has far too much amperage draw and you are running the rick of melting connectors, wiring insulation, and possibly starting a fire. Now, if the voltage regulator is not out-putting a correct voltage for charging, you need to check the stator...

The stator check will have you reading the AC power coming off the two yellow wires before they get to the regulator. Usually, depending on the system, this will be in the 30-60 volts AC range. You will also do a continuity check on each wire to see if the stator is grounded to the engine case. If the stator is good, but the regulator output is not good, chances are the regulator is bad....

In some rare cases, the new battery is bad, will not take a charge, and it makes the charging system run excessively hard (I had this happen in the past with a brand new Interstate brand battery in teh 90's).

[Howie]

Assuming you checked the stator, as in an earlier post, I would buy the new Electrex.  There is no way you know what you are buying on Fleabay, and, AFAIK, there is no way to bench test one.  Since the part is electronic, the seller can say you cooked it anyway.  My advice is buy the Electrex from Chris Kelley.  Many have run these with no problem and they are much cheaper than OEM.