Bitsyncmaster
02-06-2022, 01:46 PM
I measured the current of the blower motor with the engine running. Note my alternator puts out 14.7 volts at idle so you may get a little less current if yours has less voltage. I think my blower is original. I've never changed it but bought my car 15 years ago. I also measured the voltage on the blower motor so I could compute some other values.
Speed #1 is 3.07 amps with 4.1 volts, computed motor power is 12.6 watts
Speed #2 is 6.95 amps with 7.9 volts, computed motor power is 55 watts
Speed #3 is 11.55 amps with 11.2 volts, computed motor power is 129 watts
Speed #4 is 15.1 amps with 13.3 volts, computed motor power is 201 watts
Wasted resistor power computed is:
Speed #1 = 28.2 watts
Speed #2 = 37.5 watts
Speed #3 = 24.3 watts
I was thinking of making a PWM circuit to drive the blower motor to reduce blower current on the first three speeds but so far don't think it's worth the effort. I could have a continuous variable speed though and even make it change with cabin temps. Also a very minor AC cooling not adding that resistor heat to the air flow.
Speed #1 is 3.07 amps with 4.1 volts, computed motor power is 12.6 watts
Speed #2 is 6.95 amps with 7.9 volts, computed motor power is 55 watts
Speed #3 is 11.55 amps with 11.2 volts, computed motor power is 129 watts
Speed #4 is 15.1 amps with 13.3 volts, computed motor power is 201 watts
Wasted resistor power computed is:
Speed #1 = 28.2 watts
Speed #2 = 37.5 watts
Speed #3 = 24.3 watts
I was thinking of making a PWM circuit to drive the blower motor to reduce blower current on the first three speeds but so far don't think it's worth the effort. I could have a continuous variable speed though and even make it change with cabin temps. Also a very minor AC cooling not adding that resistor heat to the air flow.