Had the same problems on my 916 and my RD350 and it's normally due to border line rated connections and corrosion. You need to upgrade the joint, what I did was cut the old ones off and go to your local truck parts supplier and buy 50 amp connections. Put these on with electrical grease in the connections before you snap them back together.
The benefit of the bullet connectors is that you can check Insulation and continuity, easily isolating the rest of the motorcycle.
Funny how forums change over time and things are forgotten. This was a common problem a few years ago but most of the 916/748 models will have been sorted back in the day. The wires from the alternator and the plug are not up to the power they have to carry The common fix is to replace the wire from the alternator with heavier duty wire and then fit a connector or connectors that can take the amps. Didn't hear of many fried alternators but it is likely that the rectifier has gone kaput You can get a better cheaper rectifier from Electrex
The exact problem I had..... I bought my 916 4 years ago but it had lay for 8 years previous without being fired. It needed the best part of a restoration before I even put a battery in it and it lasted 5 miles (on the way to the MOT station) when the connections went into melt-down and all the smoke escaped from the reg/rec. I checked the alternator ac output and it was within tolerance at the various revs so it was a chicken or egg scenario, what fried what first? Anyway, the upshot was to replace the connectors with 50A items and fit an Electrex World reg/rec with the additional heatsink/exhaust shield off the 996 and an air deflector glued to the inside of the fairing lower duct to direct actual air onto the unit and not just pass up the fairing panel and out again at the clutch.
I'll have a look for some of those powerpole connectors tomorrow . The bike seem to be running fine except for it not priming and that's the only reason I came across the burnt connector
no offence intended VtwinDave but this subject is a very popular one. Because this Forum has no 'sticky' section and people aren't encouraged to use the search function, the result is that the answers get patiently repeated over and over and over. The following threads (and these are only a fraction of what's on here) might help you get a better overall picture : - 748 Problems | Ducati Forum 1997 748, 2 wire alternator output??? | Page 2 | Ducati Forum Monster M600 problems | Ducati Forum Thinking of a 996?! | Ducati Forum 996 New Regulators on E-bay | Ducati Forum 916 strada........ Smoking wires?? | Ducati Forum Battery/rectifier woes | Ducati Forum
It actually has nothing to do with the stator condition or the guage of the wires but is all about the connector itself. The connector is subject to water ingress, either through exposure to water during riding (eg, in the rain) or through washing, or just through water in the atmosphere. Over time the metal pins will begin to corrode in the connector. Part of that process means the oxidisation layer that builds up causes the resistance of the connector pins to change, as the oxidisation layer is less conductive (higher resistance) than the metal it grows on. As the oxidisation layer gets thicker, there comes a point when the connector becomes the highest resistance part of the circuit. This high resistance will have the side effect of a lot of heat (A LOT!) until it comes to the point where the metal pins are effectively a heating element. It won't take long for these to melt through the plastic connector, at which point they can touch each other and short circuit your stator output. This is what creates the nice burnt connector. The simple fix is to eliminate the connector itself. This only becomes an issue if you wish to dismantle the bike in future as it means that the stator is permanently wired to the reg/rec! You could replace with another connector but you are likely to have the same problem again in the future unless you live somewhere that your bike is not exopsed to water - I hear Mars is pretty good. If you do replace the connector, get it checked with each service to remove any corrosion as this will keep on top of the issue and stop it from happening in the future.
Great response! Interesting that the first sign would be weak battery and starting. Presumably though, it wouldn't apply to a battery charged by a charger, so a good test would be to try charging with a charger and if the battery then starts the engine easily, suspect these connections?
Whereabouts is the connector, if it's subject to water ingress from washing and riding? I'm confused, Air Con Technical's answer seemed to imply it was inside the casing but if it's subject to external water ingress, does that mean it's outside the casing and can be checked and or replaced relatively easily?
No implication made nor meant. The stator is located within the engine. It has a connector within 100mm of the wires leaving the left hand side of the engine.
The connector block with the 3 yellow wires (or two if it's an earlier 2-phase system) as described in the first post of this thread and pictured in the second post on this thread, to which the advice relates. The connector joins the coil that is bolted to the inside of the left-hand engine cover to the reg/rec which is located on the right-hand side of the engine below the battery on the 916 design. As I said, it's nothing to do with the coils or wiring, but all down to that connector going high resistance through corrosion that causes the issues described in the first post and seen in the picture in the second post.
Thanks for that. Obviously the alternator has to output to the battery via the regulator/rectifier but where this connector is located along the length of that wire is less obvious unless one hunts for it, dismantling as necessary in the process. I have a 999 with piggybacked starting circuit cables, so learning that this connector is behind the battery box doesn't seem like good news to me as it sounds as though checking the condition of it is likely to involve undoing and redoing what was a right pita in the first place. Less of a pita than suffering the consequences of it developing too much resistance due to corrosion and overheating though...
Is it possible to re-route the cable so that the connector is above the battery box? I'm sure I've read that somewhere.
No one said it is caused by the stator, so why do you state that? The stator can easily become damaged and burnt out by this connector going high resistance. Your advice is after the horse has bolted. The op didn't ask how to avoid it, just how to fix it. Typical exam failure; answering a question that wasn't asked.
It should be easy enough to find as you can easily see the alternator coil wires coming out from the left-hand side of the engine, just in front of where the water pump is and, as you say, behind the battery mount. The reg/rec is located just in front of this, so the wires are much shorter and don't cross the engine, and should be easier to find and get to! I'm not sure if Ducati upgraded the connector on the 999 range from what was used on the original 916 line but they certainly seem less prone to this happening. The problem may well date back in the 350W charging system that the original 916 had which was changed to 500W to allow the bike to run both dipped and main beam at the same time and still have overhead to charge the battery. It's quite likely that this connector was overlooked for a similar upgrade to one with a better/improved design and/or seal.
