I have been putting together a small robot using an Arduino Motor Shield R3. The shield has two sockets for motors, however the wheel carriage I bought has four motors. I tried putting both right side motors in one socket set, and the left side motors in the other socket set.
When I turn on the Arduino, the left side motors turn together according to how I coded the board, however the right side behaves differently.
One of the motors does not start. If I push it a little it will start turning. Though not always. When I plugged in the misbehaving motor by itself, it runs correctly.
I am wondering about cause of the problem here. Is it likely the second motor on the right side is faulty? Or am I trying to use up too much power and disrupting the current?