Need help chasing a bad ground.

[user_name]

I picked up a 2008 Lifan 110cc a little bit ago.

All is well functionally except for the headlight. When in neutral, the headlight works perfectly. Shift out of neutral, and the front headlight and indicator lights go real dim, the rear lights all work perfectly.

neutral with right turn signal, everything bright and glorious.

in gear:

I come from the mountain biking world, so I don't have much for knowledge of electrical systems.

Through the guidance of others the diagnosis ofa bad ground seem to fit the symptoms.

Here's where it gets a little sticky. I went through all the wiring I could get ahold of and found two wires that were switched, but that didn't solve my problem. I can't spot anywhere where it looks like the coloring of wires is messed up. I went through unplugging each switch and checking if the headlight still went dim when I switched into gear and couldn't find one where the problem was eliminated.

If the neutral switch is unplugged, the headlight is dim all the time. So only in neutral with the neutral switch plugged are the headlight and turn signals happy.

I don't have a wiring diagram for it. I have a lifan 110gy-3, but the manual I was given is for another ct70 replica bike. It's close, but not 100% the same. I was able to find this, which seems good to me, but the colors don't match up which is kind of frustrating.

I did find a green wire behind the headlight that splits (bottom, about 7:00 in the picture), and there is only one wire coming off the connection which goes with a pink wire to the left hand controls. This seems to be of the ilk of what I should be looking for, only I have no idea to how to find what might be supposed to go in the other half of that split, if there is a ground missing or if there is one going where it shouldn't go.

What should I do next to help chase this down I guess is my question. Does this sound like anything specific?

I can get my hands on a meter if that would help. Any help on where to go next would be greatly appreciated! Have a good one.

 

[my67xr]

i would start by finding the green wire which will come off the back of the headlight globe plug
secure another earth wire from a frame bolt/screw etc, make sure the frame is bare metal (use some sandpaper etc to clean the paint off) and smear a little grease on it to stop it rusting.
and once the new earth wire is screwed/secured to the frame, run the other end of the wire to the green on the back of the headlight globe, then test it again.

 

[motodevo]

Get some scrap wire, attach one end to the negative battery terminal, and the other to the green wire in the headlight bucket. If it fixes it, check the ground coming off the battery first. Haven't played with a china copy, but i know with real ct70's if you repaint them you get earthing issues like you have, they need to be earthed on the inside of the motor mounts, the tail light bracket, the ignition switch, coil mount, etc.

 

[user_name]

I got tired of chasing, and since the fork stanchions are conveniently right there and steel, I just cut and stripped the end of the ground and threw a few turns of electrical tape around it with the wire on the fork. Problem solved.


Thanks for the responses.

 

[matty_77]

Ive put a 140 in a postie before, I kept the original wiring and just changed the cdi. I would be getting a genuine 110 honda wiring loom for your bike.