Last sunday i was out with my kids and i hit the kill button on the remote on my sons tao tao 125g. He went to restart it and nothing. i tried starting it w/ the remote it fired right up. now it seems like randomly the switch on the handlebars will start it. I now rely on the remote to start it. Any ideas where to look?

 

Without the remote module the quad has a startup safety interlock which prevents the quad from starter motor from turning unless the:

1) Fuse is good
2) Ignition is on
3) Brakes are applied
4) Start button is pushed
5) Your starter solenoid is working
6) Your battery and starter are good
7) All the wiring connecting these things is good

When you start the quad with the remote you are bypassing steps 2,3, and 4. Sometimes if the remote was added as an after market device you are also bypassing step 1.

Since your quad is starting with the remote, we can eliminate step 5 and 6, and part of step 7.

Questions:

A) Turn on the ignition switch and apply the brakes. Look at your brake light. Is it lit up? This is necessary for starting up your quad with the start button. It is not necessary with the remote. This test will give us an important starting clue.

B) You say it sometimes starts randomly with the start button. Correlate this behavior with whether your brake light is on. Also correlate this with wiggling/playing with the start button. Do the same with the ignition switch. And do the same while wiggling the wires going into the brake switch, ignition switch, and start button. See if you can narrow it down to a single assembly...

C) If step B above doen't lead to success, the disassemble the plastic covers enough to expose the wiring to the ignition switch to main wiring harness connector, the left handlebar to main harness connector, and the the brake switch(es) to main harness connector(s). What are the colors on each of those connectors, but give me the colors only (this is really important) on the the wiring harness side of any connector. I don't care at all about the wire colors going up the short pigtail wires to the actual ignition switch, or the the brake switch, etc. I only want main wiring wiring harness colors. Again, this is really, really important. I need this info to piece together how your wiring harness is actually wired, so I can compose the next needed points to measure with a meter.

Oh, and you'll need a meter. Normally I rail against test lights. They have got to be the most worthless piece of test gear ever invented, but I expect this problem is going to be so easy that even a test light will be able to let you solve it.