Electrics Help needed (12v DC Wassell)-No lights/horn

[purple_pill67]

Can anyone give me any pointers as to what and where to check to figure out why my lights and horn have stopped working, bike starts/runs no bother.
I have casa loom+ign switch/indian stator+flywheel/orig spanish light switch/h4 converted headlight/bgm led rear.
Running DC Wassell with battery.
I have a multimeter but unsure what to check and what readings I should get to rule bits out.
I charged the battery on a batt charger and got a reading of around 13/14v but the reading was constantly going down by 0.1v.

[coaster]

Do you mean that the voltage was falling with the battery connected to the scooter and the engine running? A standard Indian stator will barely give out enough wattage to power an H4 headlight (if it's 55/60 watt) unless the engine is revving above about 3.5k rpm even with an LED rear lamp. If you do a lot of slow or town ridding you wiil need to top the battery up from the mains from time to time. The BGM stator gives a little more though. I have exactly the same problem and on the way to Davos for the Euro Lambretta meeting a few weeks ago I had to swithch the headlamp off on the motorway sections in order to keep enough charge in the battery for my satnav, Garmin and iphone.

If it's loosing charge without being connected then the battery could be on its way out.

[purple_pill67]

The battery was losing power off the bike, just connected to multimeter.
I havent had my lights on much before they stopped working as its light when i go to and from work.
I vaguely remember leaving the light on all day by accident which obviously wouldnt do much good. It should be getting enough revs to keep it somewhere near level on the charge/usage. I get absolutely nothing lights/horn wise at all even after being charged off the bike.
Would a knackered battery cause the problems? Could i connect up the charger to replicate the battery to see if that would at least gice me something.
I do have a BGM DC stator ready to fit when i change the top end soon.

[coaster]

The battery should give you a stable 13 volts off the bike with just the meter connected. It might fall a bit when first disconnected from the charger but it should continue to hold at around 13v but if it just continues to fall for an hour or 2 then I'd say it's time to get a new battery, they don't really like heat or vibration in my experience (been through a few). I have re-wound (by me) lighting coils on my stator but the charge into the battery is minimal with the lights on. I run with a small digital volt meter connected permanently and the charge drops to around 11.5 volts with the lights on even at around 50mph. I will also be changing to a BGM stator in the near future.

[Monty]

Just a point you are talking about the battery and if it holds a charge. But with it fully charged your lights and horn should work, without the engine running if only for a limited time. No lights = wire off.
I did the same as purple pill67 and left my lights in park position in the shed. Flat Battery and no way was it going to take a charge again. I could get it to 8 or 9V but it would be flat in seconds.A new battery sorted that. You need to measure what the Wassle is putting out between the red and the Black with the bike running. 13.5 is what I would be looking for. if its down at 7 or 8 you may not be benefiting on the battery replacing the smoothing action,fitting a 24v 2200uf Capacitor across red and black will help. Get your 13 v at the Wassel end then check your headset end and follow it through

[purple_pill67]

Just done a couple of readings, both not good ones im guessing
0.8v across the battery and 1.01v between wassel red+wassel black.
Does this mean both Wassel and battery are knackered?

[Monty]

If its with the scooter running you are not outputting anything.
1st is the Meter set to DC not AC.
You will not get any meaningful readings on AC with a Wassel

[purple_pill67]

those were AC readings but the DC were about the same
wassel was with scooter running, revving did hardly anything.
battery was not running

[coaster]

I reckon your battery is fekked, the wassel will shunt all current to earth if it doesn't see a load. I suspect those readings were with the lights off? try turning the lights on and taking the readings again. If you still don't get a decent reading then it could be either the Wassel or the Stator. The stator is very easy to check, just disconnect both yellows from the Wassel and connect your meter across them set to AC. You should get a reading up to 30+ volts when you rev it.

[purple_pill67]

So a new battery will be on order anyway?
Yes, with the lights off, ill try again and check the yellows later/in the morn.