So, I am working on my nephew's Taotao 125D atv. He was riding it and now all of the sudden it wont start. It was sitting for a year after this issue. I brought it home and the first thing I did because it was cheap to do so was order a new battery, carb, starter, and wiring harness (https://www.amazon.com/dp/B07T9J8DSW?ref=ppx_pop_mob_ap_share).

I found that the harness did not match up exactly to the existing components. For example, it was setup for two headlights (male connections on the harness). There were two two-pin connections left on the front-end of the harness, but I couldn't determine which was for the starter button and which wasn't. Not sure what the extra connection (remainin two-pin on front-end) was for. It didn't have the hookup for the transmission gear indicators. It didn't have matching plugs for the existing foot brake (male two-pin) and rear brake (three-wire male slide connections).

I went ahead and connected the new harness, which came with all new components (see link above). I attempted to start and got nothing. I tested the solenoid and it was good- engaged and got continuity. I jumped the solenoid and got spark. Installed plug, jumped again, got it running. It would appear to be some disconnect between key switch, kill switch, and safety switches in between.

I tested the key switch and it is getting power. When I turn the key to run it is trasferring power to the other side 12+ volts. I haven't tested from the switch to the start button yet.

I'd like to get a proper harness that'll fit directly to this model, but havent been able to locate one. Any help is appreciated. Also, any help trying totraceto trace back the issue is greatl appreciated. I'm not too good with wiring, but can follow along well.

 

Those universal wiring harnesses are rarely "plug and play". I always advise that if your electrical skills are good enough to fit one, they are good enough to fix the harness you already have. Anyway, keep going through the starter button circuit. There are several ways it can be wired, most use pos from ignition switch to start button, when pressed this sends pos to one side of small wires on solenoid, but lock-outs can involve the wire going from ignition switch to brake switch, then to start button. Others use the negative side for start button, or lock-out. Most of the big makers complicate things further with relays and diodes operating lock-out circuits.

 

Thank you for yoir reply. I am new to the forum and appreciate the help. Yesterday evening I continued checking the components as best as possible. I found that the key is getting power to the starter button and that one side of the solenoid small wiresis hot as well. This thing used to have a safety tether and pedal brake sensor that enabled starting in addition to the hand brake which would also enable starting. I removed the tether and pedal brake and I am going to test continuity on the hand brake circuit today. The reason I didnt attempt to fix the old harness is because it sat for a while and mice did a number on the wires. I wish I could have used the original though; I'm sure I'd be done by now if I had been able to. In absense of finding a direct fit harness, I will probably end up customizing the universal to fit. If so, I will probably remove all safety circuit wiring except the hand brake.

 

Well, I spent a good 4 hours today messing around with it. For whatever reason, I couldnt get power to the solenoid actuator. I was able to trace back the power from the battery to the key to the starter button. However, it ended there for a little bit. There ended up being an open male connection with no match. When I jumped that wire, I was able to get it started with the push button. The funny thing was none of the safety hookups worked. The key shutoff and kill switch worked though. So, I was happy and ended up getting it all tied up nicely and put back together. Runs like a charm again.

 

im having the same issue not getting the quad to start from the starter button. I have the same extra plug With 12v towards the rear of the machine. What did you jump to get things to work?
glad I stumbled upon your post

 

I was using a universal harness. I traced the power all the way from the battery and found that there was a dead end in the power line. Meaning, there was power on the hot side, but nowhere to plug it in. So, I clipped a matching connector off the old harness, fashioned a wire that when from one side of the connector to the other, and plugged it into the dead end lip. After that, it workedlike a charm. Just remember, the starter line is a big circle and when you hit the starter button you complete the circle. If you are getting power to the starter button and after it when you press it, then thereis a break in the circle after the button.