Too much currentr or amps is the reason why your voltage reducer smoked. Reason for hi current is unknown. Could be operator error or a failed component like wiring insulation. On the other hand. One very common mistake is a mismatch between what your gauge wants to see, resistance wise, from your sender and what ohms value sender you installed. BTW, there are many pervious posts on this subject with a number of troubleshooting hints to help solve the problem.

Six volt guy living in a twelve volt world