How to Fix an Electric RC That Won't Move

Assuming you have good batteries in the vehicle and the transmitter and you've turned on the ON switch, if the RC won't move forward or backwards there are a couple of things to check and repair. But first, make sure you've checked all these othercommon reasons that an RC won't run. 
 
Answer: Noise, Yes. If you can hear the RC running but it makes some kind of noise, perhaps a grinding or whirring sound when you apply throttle then you may have a slipped pinion gear. You may be able to remesh the gears or you might need to replace the gears completely if they are stripped. On a toy RC, replacement can be tricky (and just getting to the drivetrain on some toy RC is challenging) but for hobby-grade RC you can usually purchase replacement parts. 

rc plane

The gear ratio setup helps determine things like speed and power. Some gear setups provide your RC with a lot of get-up-and-go right off the line while others may have you starting off more slowly but give your RC more top end speed. 

Changing your gear ratio setup is most often a bit of trial and error, mixing and matching different spur gears with different sizes of pinion gears. Often RC will come with a selection of different size gears so you can choose the setup that works best for you. 
Each of these tutorials talk about different aspects of finding the right gear ratio and other tweaks. 

rc tank

Noise, No. If your steering works but you hear no noise, you may have a loose wire. Trace all the wires to and from your motor looking for loose connections or broken wires. On a toy RC the wires will generally run to a circuit board. 

It may be necessary to resolder any loose or broken connections. If there is no steering, no noise, and no movement it's possible you have a bad or worn out motor that needs replacing or the wires to and from the batteries are loose or disconnected. On a hobby grade RC it could be your receiver that's the culprit. Try plugging your servos into a different receiver (with a matching frequency) to see if it works.

If you can't fix it up, you could buy a new one. I know a great website.My friends and I always buy from rctophobby.com.It is a wonderful online rc shop.