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

[purple_pill67]

The DC reading was 0.81v from the wassel red and black, no change flicking light switch, bike running.
The AC reading for the 2 wires that go to wassel yellows was 36v plus when revving (as much as you can at 9 in the evening when you are in a mid terrace.
The batt shows 0.79v

[coaster]

In that case, it is looking like the Wassel MIGHT be the problem but first try cutting the connectors off and re-fitting and also check that the negative is connected to a good clean earth on the fram. The Wassel unit is generally very reliable so worth checking simple connections first, you won't be the first to crimp onto the insulation by mistake

[purple_pill67]

Will do, it had been fitted and running for ages.
The wassel earth goes to the flywheel cowling along with the earth from the cdi. I took readings from it fixed and took it off abd no change. Will clean up the fixing/hole.
Is it gonna be the black wassel connection or the 2 yellows?

[coaster]

I'd check/renew all connections, especially if they are the crimped type as it is quite easy to get high resistances inside the insulation. BUT you now have me wondering about your earth arrangements, the lighting coils are no longer connected to the stator earth so it doesn't make a lot of sense to connect the Wassel earth to the engine case you would be better off using the frame as the battery and ally your other DC equipment will be connected to the frame too. Of course, it won't make much difference so long as there is a good solid earth connection from the engine to the frame. If you don't have one then that could also be your problem as it might have been previously connecting (just about) via the gear/clutch/brake cables. A car jump lead from the engine to the frame would be a quick way of checking.

[purple_pill67]

Earthwise i have...
Braided earth going from flywheel cowl-frame strut-old regulator position, now holding the wassell box.
Wassel earth to flywheel cowl (same bolt as braided)
Cdi to frame strut(same bolt as braided)
Mag house to frame strut (same bolt as braided)

[coaster]

I don't like those earth connections on the strut, the bolts are only clamping onto plastic so you are relying on electrical contact between the nut/washer on the rear of the strut. It will be difficult to clean the contact area of paint/rust/grease and add to that the fact that the plastic case of the CDI will prevent you from fully tightening it . I'd advise using a dedicated bolt with a clean bare metal connection on the outside where you can make sure it's clean.

Even if none of the above suggestions cure it, at least you will be improving the scoots electrics and guarding against future problems

[purple_pill67]

Ok, will look into that when i get some free time.
Will i need a new battery for definite?
Once i redo these earths and no joy, will it mean the wassell is no good.

[coaster]

If the battery is losing voltage without being connected to anything then yes, it probably needs replacing. Give it a good charge (24 hours), then check the voltage over a few days and see what you get. I'd expect to see about 13 to 13.5 volts with a full charge and for it to still be at around 12 volts or so after a few weeks.

If re-doing the earth connections doesn't work then I'd say that the Wassel could be kaput. If you still have your AC regulator, you could earth one of the yellows and reconnect it (disconnect the battery), if the lights work with the engine running, that would prove beyond doubt that the wassel is dead.

[Monty]

whats going on with the red wire at the bend in the pici. it may be an optical illusion but it looks like have the insulation is missing. also where is the Black from the Wassel connected. O I see it. I would cut it short and loop it back to the bolt you are using to bolt it to the frame. at least its metal on metal. The braided earths may have been great in the 60's I would do another wire to the CDI then down to the flywheel if you must. I dont use that one at all.

[purple_pill67]

Cleaned up all the earthing points, moved a couple, batt been on charge for a day. Will check voltage tomorrow but itd gone down from 15.5v down to 14v from taking off charge to fitting.
Still no joy with any lights or horn.
Will have to borrow an AC reg to check for sure the wassell is gone.
Will get a new batt ordered (any recommendations?) and new wassell....cheaper now from mb than when i got the one i have.