Ducati.ms - The Ultimate Ducati Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
350 Posts
Discussion Starter #1
I discovered that my charging system wasn't working. I found a short between the two yellow wires that go to the voltage regulator (must have cooked the wires at the last trackday). I have not hooked everything back up, but have a question.

When I use a multimeter, by putting the probes on each end of the connector terminals, to see if there is another short some where else down the harness, I get continuity. Should I get "OL" (open) or are the wires connected within the cases? I really don't want to have to keep cutting the harness up or pull the side cover off to keep looking.

Thanks,

John
 

·
Registered
Joined
·
3,883 Posts
They're connected to the stator coil. It's one big winding (set of windings), but it's large wire, so the value will be low. Maybe like 1 Ohm or 0.5 Ohms. Should be Open (OL) from windings to chassis. If you separate the wires, unplug it from the RR, and measure into the 2 yellow leads, you should see about 10 to 20VAC at an idle, and it should go up with RPM (Like 40VAC at 4000rpm.)

FWIW, the yellow wires have been a problem spot on the older machines. Especially at the pin/barrel connectors. A lot of people just bypass the connector. If the entire yellow wires are ruined, you could replace with #10 AWG wire for as much as possible. If they're fouled right at the grommet on the engine case, then you probably should replace all the way to the stator.
 

·
Registered
Joined
·
350 Posts
Discussion Starter #4
I should have clarified my impedance measurement.
I recall that I am measuring 0.4 ohm.
What I'm having difficulty with is differentiating that measuremnt's meaning that I have yet another short, or all is well from one pin through the winding to the other pin. I was hoping that the impedence of a "good" set up was something like 1Kohm. Then I would know that I'm still shorted someplace.

Since I did find one spot where the wires were melted together (now fixed), I'll have to start the bike, and check the output to see if I'm getting at least 13ish volts necessary to charge the battery.
 

·
Registered
Joined
·
350 Posts
Discussion Starter #5
I'm getting 13.4 V at 2000rpm, so I guess I only had one short.
 

·
Old Wizard
Joined
·
3,006 Posts
Stator Wire Repairs

The error that most people make is replacing only the 6-inches or so of the crispy portion of the stator lead wires adjacent to the connector. Even though not visibly damaged, the adjacent section of wire should also be replaced with a larger gauge all the way back to where it enters the engine casing. This is because the entire wire has been overheated and has lost its electrical insulation properties which then allows the wires to short together (likely within the common sheath), usually at the higher voltages produced at higher engine speeds but sometimes also at lower rpms.

This wire shorting will damage the regulator at some point.
 
1 - 6 of 6 Posts
Top