The blower motor in my wifes 2001 V6 went out. Replaced it with a new motor from NAPA. It worked great, all the speeds and settings worked for about a month and one day the motor burned up and filled the car with smoke. I figured it was just a defective motor and took it back and swapped it for a new one. Put the 2nd new motor back in and here i am a month later and it burned up again. What could be burning up the motors?