Happy new year everyone!
I have been having charging issues with my 07 Cali Vintage. After a struggle I managed to remove the dynamo cover to check the stator and I found that the black connector has snapped off, as you can see in the image…I imagine that it isn’t a good thing and that it would have to be replaced (unless can be repaired), if someone could confirm that, I would be very grateful.
Cheers
Shawn
The black tab held on with a tie wrap doesn’t look like a connector. Did you test the voltage across the battery terminals before stripping it down? You should see about 14volts at around 2000 revs. If you refit the stator and start the bike, check the voltage from the stator across the 2 output wires. This will be AC so set the meter accordingly.
There’s a thread on the Wild Guzzi forum that might give you a few hints to look at
Hi Don, thanks for the reply, I’ll be getting the battery replaced over the next couple of days then I’ll be able to test. I will also check out the thread.
Cheers
Shawn
Hi Don,
I finally managed to test the stator, the image shows the output at 3000 rpm, don’t know if that is a good thing. Anyway, I connected it all back up and the battery showed charging at 13volts…
I’m inclined to think that there may be a bad contact as it cut out after a few yards of riding.
13 Volts is not an unreasonable voltage, particularly if you had the headlight on.
I can’t see what the scale is on your photo, 64.3 what?
Ah yes…64.3 volts AC…
That sounds like the charging system is working.
You say it cut out after a few yards riding, that wouldn’t be due to a charging issue, it would either be fuel or ignition.
The AC voltage may well be considerably higher before the diodes. I would measure the DC voltage at the battery terminals - before the generator excites and then watch as the generator light goes out. Then rev the engine to say 5000 rpm and see what he DC voltage rises to.
For the AC I would be more interested that all three were more or less the same measuring phase to phase (yellow 1 to yellow 2; yellow 2 to yellow 3; yellow 3 to yellow 1).
I fitted a new Lucas rectifier and multi use Voltage regulator from Ebay. The generator puts out a decent charge and voltage ~ 13.8 DC above ~ 3,000 rpm, but the engine does like a bit of beans to excite the stator, and it de-excites when back at idle, but this might be because the load resistor I am using to provide the field excitation current (in parallel with the generator lamp now a LED) is under powered at 2W (68 ohms) and I might try a lower resistance resistor, or simply add another 2 x 68 ohm 2W series connected, but in parallel with the first resistor. I know this sounds complicated, but simply wiring another 68ohm 2W might increase the field current too much.
PLEASE IGNORE AS THIS APPEARS TO BE THE TWO WIRE SINGLE PHASE GENERATOR VARIANT. I WOULD NEED TO STUDY THE WIRING DIAGRAM TO WORK OUT HOW THESE ARE EXCITED AND CONTROLLED. (I deal with high 400volts 3 phase systems for my day job BTW).
This guide suggests using a 100 ohm resistor to replace the charge light.
Excellent booklet.
My ohms law calc told me ~ 70 ohms with 68 ohms the nearest standard size. I am going to try reducing that to see if it makes the stator excite at lower revs. If I wire another two 68 ohms in series then place this pair in parallel with the existing 68ohm that will reduce the resistance to ~50 ohms. If that does not work I will try going higher, but lower resistance = higher field current flow = earlier excitation (I think).
She is up and running again, managed to figure out the problem, it was as I thought…a bad connection, with the 30amp fuse. 
took her our for a ride and all is good, battery was charging around 13.5 volts.
It is so good to be back up and running.
Thank you Don and everyone else for their input!
It was really appreciated!
Cheers
Over 90% of electrical defects on anything are due to bad connections. Bikes, cars are boats in particular are very susceptible due to the conditions in which they are used. At least with the bike no seawater is involved (unless you’re having a really bad day !).
