Why Won’t My RC Car Move (Electric)?

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Keeping an RC vehicle running continuously is a hard job as parts will wear out as time passes. However, you sometimes may find your RC won’t start up despite you keep it maintained. There are many visible and invisible factors that may cause the malfunction of the RC car. The following post will list out the reasons and provide a simple solution for them respectively.

There are different components that may affect your RC car:

Forget To Check Your On/Off Switches

The first thing you should check is your on/off switches.  People usually overlook the obvious.  You might just forget to turn on your switch on your transmitter or  RC car.  Also, check your transmitter if you have more than one transmitter at home; you might just bring the wrong one for that particular car.

Stripped Gears

The gears of your RC car might have been stripped since the last time you played with it.  Getting your gears stripped can happen if you just upgraded to a brushless motor without replacing the plastic gears with metal ones.  That is the reason why you need to perform regular maintenance for your RC car.  Every time after you use your RC car, you should check if any screw or gear needs to be tightened up, or replaced.    You might also need to realign your pinion with the spur gear.  If you hear a grinding noise; it is time to check the gears.

Bad Connection With The Motor

A bad connected motor is the most concerned issue in many forums. The main reason is the wires are not connected to the ESC correctly, causing it fails to function. As some people may ignore the user manual, it usually guides you on how to wire the motor with the ESC.

The wires of an ESC are usually come in three colors (brushless), blue (A plug), yellow (B plug) and orange (C plug) or two colors (brushed), blue (A plug) and yellow (B plug).

For the brushless motor, the motor will run once you connect all three wires.  If the motor runs in the wrong direction, you need to reconnect two of the three wires.  For the brushed motor, you can usually connect the yellow to the red and blue to the black.

For connectors, there are mainly two types of bullet connectors so you should acquire pairs of female and male connectors from your local hobby shop if you need them, but they are usually included in the kit.

Some vehicle types require maximum performance such as drift and touring cars. However, connectors will create resistance between the connection, causing the motor can’t operate at its max performance. To eliminate the problem, just connect the wires from the ESC directly to the motor.

Fig.1 connecting the wires directly to the motor

To make a good connection between wires, you need to learn how to do soldering and have access to a good soldering gun. If you are an RC beginner, you should spend some time to perfect this skill as you later will find it very useful in your hobby. You should also buy a third-hand soldering iron stand for holding your wires during performing soldering.

Here is a YouTube video to learn how to do the soldering for RC cars. 

Your Electronic Speed Controller (ESC) Stopped Working

If the motor doesn’t move but the wires are connected correctly, it is most likely the setting on the ESC has messed up. The ESC is the module that controls the running ability of the vehicle. The settings you will be looking for is the neutral throttle point.  At the neutral throttle point, the wheels should stop.   But, when you turn away from the neutral throttle point on your transmitter, the wheels should run, if not, it can also have a bad connection from the ESC to the motor.

The solution for a bad connection is simple; a quick change of connectors or rewiring will do as mentioned above.

For the settings on the ESC, you read the user manual carefully and adjust the throttle neutral point accordingly.  Sometimes, you need to reset your transmitter to the original factory setting in order to make it work.

Another source of the problem is the overheat of your ESC.   For this problem, you just need to put the RC car aside for a while, it should work again. It is due to the fact that every ESC has heat protection.  Once the ESC’s temperature is above a certain degree, it will stop for a while until the overheating problem is gone.

To prevent overheating, we should use a smaller pinion (to reduce speed).  Another way is to put a fan on top of your ESC and/or motor.   Finally, if you do not mind, you can even drill holes on your body shell.  They are just some of the ways to prevent overheating your system.

Broken Driveshaft

If all your electronics are functioning well, then you should check if the driveshafts are properly connected to the axles. The common problem with driveshafts is that they have different assembly methods across different brands.  The more expensive RC cars usually are made of durable materials and have better designs for their structures while the lower-priced RC cars have a simple design and made of less durable materials.   Thus, some of them have a grub screw to hold the dogbone and the axle while some reasonably priced RCs may just have an untightened pin with a ring to lock two components in place.

It is important to check if all the driveshafts are connected before starting up your RC.   Do check the parts according to the user manual to familiarize yourself with the structure. If all components are the same as the ones described in the user manual and you are sure that the RC car is unmodified, replacing the malfunctioning part(s) will help you a lot since it is most likely that the part(s) is broken.

Fig.5 An example of a properly assembled driveshaft

Damaged Or Dead Batteries

Batteries can be dangerous items especially when you deal with LIPO batteries since they are quite explosive when you handle them carelessly.  The first thing to remember is that never charge them overnight!!!

The materials in the batteries are quite flammable and may be explosive if it touches the air. There are several signs that indicate your battery is no good to use, expanding in size, unbalanced cell voltage, getting a lot hotter when charging, a quick drain of battery when using it.  Always, pay extra attention to all these signs.

You should always put your LIPO batteries in a safety bag.

Another common issue is that Each ESC has a different type of connector. So before buying a new ESC, make sure that the battery in your stock has the matching connector with your newly purchased ESC.

If you have not used your RC car for a while, your battery installed in the car right now might be dead already.  After you charge the battery, it will not hold any electricity.


It is important to investigate what’s wrong with your RC car when it doesn’t move. The most critical thing for us to do is to read the user manual as you will solve most of the problems there.  However, most of the beginners don’t seem to pay attention to details in the user manual.

So to sum up, there are three main steps in inspecting your RC.

  1. find out where the problem is in terms of parts.
  2. check the user manual and find if the part looks like the one showing in the manual and define if it is broken or not.
  3. Third, replacing the part or repair it.

Thanks for reading

Writer: Kelvin Wong

Edited by Carlos Santos, your webmaster.


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