G1 Grounding issue

[Rdavis984]

I am working on a gas G1. If i unplug the negative wire from the CDI magneto it will turn over. As soon as I plug the wire into the magneto the negative fuse blows. So i have checked and i am getting positive voltage from coming through the negative line. If I unplug both the switch and the throttle micro switch the voltage drops to around 7 volts. Where do I start to trace this grounding issue? Thanks

[sho305]

First thing is these carts all yamaha are ground wired the frame is not ground. They have issues with the wiring with age. So take all the ground wires you can find and redo the connections to make sure they are all working. Check all the connectors and fuse holders for good connection and clean or replace if needed. After you get that done see what you have, you didn't say if it does this when you hit the pedal, often the ground (cable/connection) for the gen/starter will get bad and it tries to ground via the 10A fuse and of course blows it. You also can't wire lights and other accessories to the frame unless you ground it you should wire pos and neg to the battery. Note the engine swingarm is not the frame it is on bushings and likely why they don't bother grounding the frame. If anything but the starter part of the gen shorts it will blow the fuse, so it should be kept in there or the small wiring will melt. There is something wrong if it keeps popping very often its bad ground wire. Look above in this forum the wiring diagram is posted in stikies there.

[LURCH]

I was having light problems and found out yamaha's had what is called a floating ground. They told me to run all ground's to the battery. Like me 1 tail light to the other and 1 headlight to the other then put them together and ground to the Neg. post of the battery.
Don't know if this helps but I'm trying to learn also.

[kcnaz]

I ran one ground lead off the battery to a piece of 20 gauge angle I had pre drilled. I have that home made ground terminal mounted behind the Yamaha name plate on the front cowling. Everything from the dash and the lights are grounded/bolted to that piece. Nothing is grounded to the frame. It works great so far.........