Blower motor current

[Bitsyncmaster]

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.

[Rhye]

I could have a continuous variable speed though and even make it change with cabin temps.

That would probably make the automatic AC possible (with a simple controller/sensor added). I've been constantly thinking of hijacking the radio display & knob (as I did in my AUX bluetooth setup) to set the desired temperature so there's no impact on the original interior.

[benose481]

[Helirich]

Interesting, but unless there’s been heat problems with those wires, it probably is not worth the trouble. (As you mentioned) Reading this makes me wish I could “upload” your talents to my mind, like in the matrix movie. Lol.