Just purchased sidewinder 3 and it came without on/off switch. I only see red and black wires. Should I just connect them?

Do the wires look like they've been twisted together? Just plug it into a battery and if it lights up, leave the wires alone. Alot of guys cut the switch off and turn the car on/off by plugging/unplugging the battery.

No, they were not twisted together. Just cut two wires, red and black. So if I connect red and black together, will I be able to start the car?

Yes you will be able to start the car. Connect the 2 small wires. As soon as you connect both power leads which will be the 2 thick wires the car will turn just like you flipped the switch. To turn it off disconnect either of the 2 power leads and it will turn off.

It may start without twisting them together. Try that first. Some ESC' switches work different than others. I'm thinking with the wires cut off, it should power up without putting them together.

As I recall, the Sidewinder 3 uses a sliding mechanical switch, not an electronic pushbutton switch, so if you don't want to replace the switch, just twisting the wires together and heatshrinking them in-place will work fine. ESCs that use electronic pushbutton switches can't be powered-on without a switch installed, because they need the momentary signal from the button being pressed to tell them to power-on.

And LRP ESCs for example, were switched on by cutting the switch off, while connecting the cables would switch the ESC off. As was said earlier: it depends. Just try both and you'll find out in a few seconds.

Wow, that's bizarre. But I suppose it's a safety feature in case the switch gets ripped off the ESC, so it won't shut off when the car is hauling ass.

I believe that's the idea behind it, yes.

Sounds like the people at LRP have no sense of excitement.