1969 CA77 Condenser

[Muddy]

Good on ya, quidger. That is a good step forward.

Because I am very remote from you and I don’t understand your electrical experience level and what tools you have, I may suggest some very basic steps to prove what is possibly wrong. Forgive me if this seems overly simplistic.

Totally disconnect the condenser from the circuit – it has the capacity to confuse things.

If your wiring and coil are standard, then the black wire from the coil should plug into the black power wire in the wiring harness. This should provide power to the coil when the ignition is turned on and no power to the coil when the ignition is turned off. Check and confirm this.

With the key turned on and the black wire connected, check you have power on the green wire (at the connector) out of the coil. This power should be present only when the ignition is turned on. Check and confirm this.

If this is correct so far, the green wire from the coil should lead to the points screw terminal. With the points open, check if you have 12 volts at the screw terminal of the points with the green wire connected and the ignition turned on. The 12 volt power supply should not be present with the ignition turned off. It is important to check this with the points open.

With no condenser connected, the points open and the ignition on, if you have power on the green connector on the coil, but no power at the screw connector of the points then you have to suspect that the wire is broken somewhere. Try a test wire from the green connector of the coil to the points instead of the wiring harness.

Please let me know what you find. We can work on the condenser after we have power to the points.

[quidger]

Thanks for being so explicit and thorough with your instructions. I’ll undertake the tasks in the morning.
I’ll report back as soon as I check each step.
I appreciate that you’ve spent so much time helping me.

[quidger]

The power at the coil, the black and the green wires both tested at 12 V . All of the testing that I did was with the condenser unplugged completely disconnected until I got to the part where you wrote “the green wire from the coil should lead to the point screw terminal.” At this point, I plugged the green coil wire into the into the male condenser connector, but I did not connect the other condenser wire with the screw terminal to the points. I was trying to follow your instructions but I was a not sure about “green wire from coil should lead to the points screw terminal”.
I checked if there was 12 V at the points screw terminal. I just got a very unusual reading to some small little numbers. There was certainly not 12 V there.
I then got a jumper wire and plugged it into the green power from the coil and put a clip on the other end of the jumper wire and clipped it to the screw terminal at the points. I got a 12 V reading and that is where I stopped.
Unfortunately, I don’t understand how the green power wire can have 12V, flow through the jumper and read 12V yet there may be a broken wire somewhere.
I the more I work through this with your help, the more I learn.
I made another short video to show what I did.

https://www.dropbox.com/scl/fi/qozhpfym ... w18qv&dl=0

[Muddy]

Good work, quidger. More steps forward which is important.

Sorry for the confusion in my notes, I was rushing things a little. I am also working a little blind as my bikes are locked away and I have only worked from memory and wiring diagrams.

To avoid confusion, I’ll just need to physically check my C72 Dream and get back to you.

Stay tuned.

[quidger]

Thanks, Muddy
Hate to have you go to a lot of inconvenience by having to access your bike.
I have really good color coded wiring diagram that I’m able to follow fairly well.
I’m glad just to follow along on that and your recollections.

[Muddy]

OK quidger, no problem at all if it gets another old Dream running.

I can now appreciate your confusion. My recollection of the wiring and the actual wiring on my bike are very different, so apologies for that. None-the-less we should be able to get 12 volts to your points with the condenser coupled.

I’m sure you know, but just in case… The condenser is actually a capacitor – an electronic device that can store electrical energy. If handled incorrectly they can discharge and give you a bit of an electrical fright. Handle them carefully, even after a long period of time disconnected from an electrical circuit. The internet will show you how to discharge them and make them safe to handle.

Your previous testing seems to confirm your coil and associated wiring is good for static testing. This does not mean they are not breaking down as they get warm/hot, it just gives confidence to proceed.

The original condenser is indeed wired in parallel to the points, but the wiring is configured so that it appears as though it is in series. To replicate this with the CL77 twin condenser we have to ensure we are wiring these correctly.

Not being familiar with the CL77 twin condenser, are there 2 sets of pairs of different colours eg 2 greens and 2 yellows (or browns)?

Do you know how to do continuity test? If so, test if there is continuity between the pairs of CL77 condenser wires of the same colours ie 2 greens and 2 yellows (or browns).

If you do not know how to do a continuity test, try this:

With the ignition off, take the CL77 condenser green wire with the (male?) bullet connector on it and plug this into the green wire with the (female?) bullet connector on it that came from the coil thru the frame. The other wire from the condenser should have the square terminal with the hole in it that connects to the points screw terminal. Connect this to the points screw terminal. Turn the motor over until the points are fully open. Turn on the ignition and carefully check/confirm you have 12 volts on the points screw terminal. Be careful as you will be charging the condenser (capacitor). If the CL77 condenser is wired correctly, you should have 12 volts on the points screw terminal.

The results you get here will dictate what we do next. But my advice would be that if the above test fails and you do not get 12 volts at the point screw terminal, repeat the test with the old condenser in the circuit in place of the CL77 twin condenser.

Please let me know how you get on.