When wiring two 12 volt batteries to get 24 volts should there be sparking when connecting the negative pole on one battery to the positive pole on the other battery?

To verify correct wiring you should have: Battery 1 Positive, to Battery 2 Negative, and Battery 1 Negative to Battery 2 Positive is series wiring, combining the voltage rating of both of the batteries. I suggest adding a "Battery Cut-Off Switch" in the circuit. Some slight arcing can happen if you drag the connectors together.

Try doing it outside your vehicle and use a multimeter set to DC volts and test for 22+ volts.