DC Motor not running on digital pins but running on 5V?

So I pulled an RS-380SH motor out of an RC boat I had but I cant seem to get the motor to run on any of the digital pins. It runs just fine on the 5V pin pulling 4.96v and 1amp I tested the digital pin I am using 9 is putting out 4.96v also but The motor dose not start with pin 9 set to HIGH but if I swap it back to just the straight 5V pin it runs just fine.

I don't understand this any help?

Note I just tried another motor a RS-360SH and it does the same thing I havent tested current draw or anything yet


You can easily damage the Arduino trying to power a motor directly from an I/O pin.

You need some sort of transistor or h-bridge to control a motor with an Arduino.


The digital pins have a limit on how much current they can source or sink. Anything over 40mA WILL damage the chip (usually just one output pin) and anything over 20mA MAY damage it.

1A going to a motor will definitely be 50 times too much.

On the Due, it gets even more complex, with different current limits on different pins - as low as 3mA.


What is your electronics, programming, arduino, hardware experience?

Thanks… Tom… :slight_smile:

wintergrasped: but if I swap it back to just the straight 5V pin it runs just fine.

Don't even run it from the Arduino's 5V pin. The regulator can't handle that much current, (it's absolute maximum is 800mA), and neither can most USB ports if you power the board that way. (500mA max typically) You definitely need an external power supply that's able to handle the motor's current.

Poor Arduino. :(

That motor has a stall current of 24A, the Arduino pins must not exceed 0.04A

You need a decent MOSFET H-bridge driver for that motor, it is high power.

...and at this point, you might need a new Arduino. At best, I would consider pin 9 to be suspect, if not toast. The regulator is probably ok (as it should go into thermal shutdown - which it didn't - so you probably got lucky).