I noticed my blower was staying on High. I turned it to 0,1,2,3 No response just stayed blowing on high. Then it stopped altogether. I read about taking the neg cable off the battery and so I did that. I turned key on and switched it and at the 3 position I the fan was blowing as if it was only on the 1 position. Turned the fan spped **** some more and then NO blower again. I know there is a relay and a resistor under dash on passengers side next to fan. My husband put his meter on and only 4 volts at the fan. This doesn't seem right. HELP! Could it be the stupid auto 0 1 2 3 4 5 switch ? 2001 S40 1.9 T

 

The control module for the A/C could be bad.(A/C controls)
The blower motor could also be bad making the A/C control panel shut the motor down.