Cycle Analyst shuts off when headlight connected

[DerekWillmott]

Hi. Can anyone help me sort this out?

I have a brand new GMAC ready to roll kit from Grin installed.
After grounding the battery negative to the frame, everything tested perfectly, including the very bright headlight (from Grin, prewired for the CA output plug). I wanted to tidy up the wiring, and the headlight had a foot of extra wire to it, so I cut it and installed a new jack much closer to the headlight. The polarity matches the original. There is no short circuit. Resistance across the centre pin and ground barrel is open with one polarity, 2 megohms with the other polarity. I also shortened wires from the brake cutoffs and the throttle, but that was before everything tested good. I did not touch the multifunction switch wire.

Now, brakes, throttle work perfectly if the light is unplugged. But, if the light is plugged into the CA when power is turned on, the CA does nothing. If I then unplug the light, the CA backlight comes on, but no information. If I then cycle the battery power, the CA comes back to life and seems to behave normally.

However, the on/off switch of the multifunction switch does not work anymore, whether or not the light is plugged in. The other buttons on that switch work normally.

At no point was the light cord attached to the CA while working on the cord. I don't see how I could have shorted out the dc power output, unless the short is inside the light. But as I said, the light worked before, and I have not tampered with it internally.

There is still battery voltage at the dc output plug from the CA, so I haven't blown an internal fuse on that wire.

Is the MFS on/off ceasing to work consistent with a short on the dc power output?

Any thoughts?

 

[DerekWillmott]

Update.
I removed the new jack from the SPL-01 light wire and resoldered on the original jack. Now plugging in the light has no effect on the CA, but the light does not work, regardless of power source. The CA works perfectly, except that the on/off button on the mf switch still does nothing. This suggests that there was perhaps an intermittent short in the light jack, though I could not reproduce it while testing with a multimeter. I still don’t know how this could have affected the on/off switch for the CA, or why it reliably made the CA not turn on when plugged in.

So now I have an SPL-01 light that does not work. With the rubber finger switch cover popped off, I can test that positive voltage into the light does not reach the positive wire to the switch. The switch works. Does anyone have a circuit diagram for this light? Is there an internal fuse? Is it possible to disassemble the light without destroying it? I haven’t figured out how yet.

And my mf switch doesn’t fully work. Does it come apart or is it glued together? Is the problem likely to be in the mf switch or in the CA?


Thanks for your help in advance.