<p><img src="https://i.stack.imgur.com/xE1dA.gif" alt="enter image description here"></p>

<p>This is what is happening to my motor. Any suggestions would help. 
1. I have tried adjusting the trimpot. 
2. Rewire the connector to match the one on the motherboard.
3. Anything else I found on the internet.</p>

If the one in your question is your
complete
code, a possibility is that your computer is just buffering the output for the serial port, withholding it in memory.  Try to add
```
```
ser.flush()
```
```
after your last line.  This command will... well...
flush
anything into the buffer through the actual connection.