Stornello 160 not charging

More problems with my Stornello 160cc Forest, It runs well starts easy, but will not charge the battery, as soon as I connect the battery the red ign light illuminates on the headlamp and that’s without switching it on, The switch appears to be a single multi switch, a combination of lights and ignition, when turning the key the light sequence works ok, nothing gets hot or smokes, the fuse I put in the system at the battery never blows, it has two fuse in the headlamp that never blow, I’m wondering if I have a faulty ignition switch, taking it apart to check it is a daunting task, has anyone took one of these switches apart?. Where would I get a new switch?.
Any suggestions, apart from set fire to it

Hi Am I right in thinking you are Jon from Norfolk way?
Are you sure the red light is a charging light. A quick look at the wiring diagram suggests that the system is the same as on my 125 Stornello from 1965. That has no charge light, the charging system is incredibly basic and consists of a diode to give basic half wave rectification of the AC from the engine and a 5 ohm resistor to regulate the voltage and to prevent the battery from overcharging. The battery only does parking lights, side lights and horn on mine. The lighting on mine is direct off the engine alternator. It looks like the later 5 speed is pretty much the same. Try starting the engine and putting a voltmeter across the battery to see if the voltage rises as you rev the engine. Don’t expect a lot as there is only 28W AC output.
I assume your key is basically a nail with a notch near the bottom. Pushing it fully in is all that is needed for normal ignition. The lights come on when you turn it, left for pilot and right for headlights.
I have recently ordered a combined electronic voltage regulator from China to fit to mine. The plan is to modify the wiring so all the AC output is fed into the battery and I will then run all the lights off that, using LED lamps.
I do have an Italian owners manual for the bike if you are needing one. Hopefully one of these links will work for you. I never get on well with Dropbox…

wiring diagram by Don West, on Flickr

Thanks for the prompt reply. Firstly, I’m in Cambridgeshire, here’s some more facts, all lights work from the battery, the key is a flat type that pushes in and turns left for side lights and right for headlamp, the bike will start as soon as the battery is connected with the key nowhere near the bike, I can run the bike for about 15 miles and then it’s game over battery drained, hopefully there’s a couple of pictures with this. Would you mind giving me your phone number through a private message.

Ooh, that’s a different bike to the one I was thinking of. Jon lives near Diss and has the later 5 speed 160 Forestier bike with the sqare cases.
I’m guessing yours is around 1968 round case 4 speed 160 and has the bulbous lump on the right hand cover over the alternator. The electrics on this one are well different to mine. Nothing like I have encountered on my bikes. I have managed to find a wiring diagram for the bike and have added it to my dropbox files so you can download it from the link below. It looks like a proper electrical system with rectifier, but I don’t see any voltage regulator. Solving your charging problems is going to have to be done by first principals of tracing the wiring etc. First thing to check is do you have an output from the alternator. The green and black wires from the alternator head to the rectifierso they must be the feed into the charging system. Next check the recifier with a multi meter. Are the diodes working correctly, ie pass one way, but not the other, Beyond that it is tracing wires and connections.
I’ll PM you my phone number.

Italian manual here
Parts list here

Wiring diagram here

Naseby by Don West, on Flickr

Few more pictures

I’ve had a dig around on the internet and can’t find anything about this one. Is there any identifying numbers or anything on the alternator body that might help searching? Edit, It seems to be a CEV 6507 alternator, but that didn’t reveal anything.
I have also asked on a couple of facebook pages to see if anyone has any experience of this alternator. We could really do with working out which wires to check for a voltage output.
Just a thought, does it have brushes, like the big twin Bosch alternator?
Studying the wiring diagram and your picture, you seem to have an extra Red/white wire connected into the board, nearest the centre on the right block of connectors, next to the orange.
I don’t see an actual charge light shown on the diagram, there is a 12V coil indictor light shown and this is on the ignition coil circuit, this will light up whenever the ignition system is live. Strange that it is a 12V 3W bulb when the system is 6V. It looks like the ignition runs direct off the battery via the red white wire circuit. I would remove that from the board and maybe look for a home for it on the switch, terminal 10 if they are labelled (between the white wire coming from the board and the blue wire that is also fed from the board).
To check the alternator, put an multimeter set to AC volts across the green wire at 10-0 o clock and the black wire at 11-00 o clock. You should get an AC voltage between those 2 connections. I would assume the green black and white wires are intended to provide AC to run the headlight, rather than the battery. It would be good to put an AC meter across these 2 with the engine running.
The rectifier output goes up to the ignition switch. I guess it should connect to the blue wire to feed charging current into the battery through the switch.
Can you add a pictue of the switch to see what is on that please.

I have had a good comprehensive answer from Facebook from someone who knows what they are talking about! As follows…

Ok. This is a combined AC/DC system. The lights run off AC that is the city run setting (low wattage light) and higher output setting for the head light. The battery is charged using one coil of the system at all times which is rectified. This provides starting voltage to coil and stop light/horn. When you put the light switch into position one city it brings in an additional coil which produces AC of enough power to run the side lights. In position 2 4 coils are used to provide the higher power of the head light. The stop light/horn has power all the time from DC side of the battery. It is not a 3 phase alternator it is single phase. The two connections on the alternator you are interested in for charging purposes are terminals 1 (common black) and Terminal 2 (Green) to rectifier from one coil. Disconnect these and put a 12 Volt bulb across these two terminals. Start the engine the bulb should light. If it does light next step is to test the rectifier. If it doesn’t the coil has failed.There is a 4 diode Bridge rectifier. The DC output is the grey cable at the bottom. Run the engine set your volt meter to to 20 volt DC connect onto to the grey wire and the other to earth. (do not disconnect the terminal) Do not worry about the polarity on the digital multimeter. The reading with ignition switch on but engine not running should be just over = or -6V(same as the voltage on the resting battery). Now start engine this reading should rise to + or -6.5+Volts possibly up to + or -7volts. The output will rise as the revs are raised. If you do see this voltage the fault is in the wiring after the rectifier. If you don’t it is the rectifier. Any Motor cycle bridge rectifier will do 6v or 12v. The wiring diagram shows the battery to be a negative earth system. Hope this helps. Just a note with these systems it is important that the wattage of the bulbs is exactly as specified. Also if the rear or front light bulb blew the other one would follow shortly in some cases.

Hope this helps and let me know what results you get from these checks.

How are you getting on with finding the fault?

Did you ever manage to resolve your charging fault?