Question Arduino GND cable is on fire

Hi I have a problem.
My simulator was complete and working.
The system is equipped with a wiper motor which I use for traction loss.
Satisfied with the result and finished the tests I decide to proceed with the cable management
but I am afraid I did something wrong and it has not worked since then.
Now when the motor starts it all goes to one side without a sense and the GND cable that goes into the arduino is ignited(catches fire).
I have already burned 2 arduino nano and now I have replaced it with arduino one 3 which does not burn,
but the GND wire still catches fire and the system blows.
I have replaced 3 IBT-2s and now put in a motor monster shield (thinking the IBT-2 was the problem) but nothing, same problem.
The question remains whose fault this problem is.

power supply?
potentiometer?
motor?

The motor if it attaches directly to the power supply works one way and the other.

What do you think could have happened?

Every attempt made so far has been in vain.

Thank you very much for your answers and ideas. Simone

My suspection is that one of the thicker ground cables which go to the motor drivers is broken. Then all the current has to come through the tiny (signal) ground wire connected to the arduino which is quickly overloaded.

Proper grounding of all components is important and any ground loops should be avoided.

Thanks guys in the next few days I will try to check.
Your ideas have made me think about the possible problem.
I am waiting for two more IBT-2 boards with which I will try again .
I will make new wiring and without hurry like last time .
I will keep you updated in case both positive and negative so that if in the future someone experiences the same problem they will find a useful precedent to solve it.
Have a nice day and thank you for your valuable support.

Hi Guys
By replacing the power supply everything works.
Problem solved.
Thanks to all for the support