I have a 88 maxima, the fan switch to blower heat and air will not work on any setting number from 1-4. The problem began went it started working only on 1(slow speed0 and 4(high speed). I checked the blower motor and the blower motor resistor, it seems they are not grounded. When I press the ac switch, the a/c comprssor comes on, the light switch does not light up and no air is blown through the vents. please help!