2015 Prius ac blower resistor??

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by DJ Moore, Jul 16, 2022.

  1. DJ Moore

    DJ Moore New Member

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    My AC has finally died after intermittent air over the last couple of weeks. The air blows very cold but the fan would start strong and fade to almost nothing. I could lower the speed to one bar and then bump it all the way back up to the highest and it would blow strong again for a while. I ordered a new blower motor and air filter for under the glove box but have read some things online about it possibly being a resistor. Can't find any video specific to a gen3 on where I can find this....any ideas?
     
  2. ChapmanF

    ChapmanF Senior Member

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    The first few cars I owned had blower resistors. No Prius has one. Gen 1 and Gen 2 have a separate electronic controller that people sometimes mistake for a resistor. A Gen 3 does not even have that; the equivalent function is built into the motor itself.

    So the three wires connecting to the motor itself are power from the battery, ground, and a signal input from the A/C "amplifier" (an ECU by any other name....) telling the motor how fast to turn.

    You can find more about that in this thread.

    [​IMG]
     
  3. Tombukt2

    Tombukt2 Senior Member

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    Older Toyotas had the ceramic block resistors and when you broke the ceramic block there were three wire windings the three speeds you get when you flip the switch as Chapman said those days are long gone. So my question is when you replace the blower motor did that fix your problem? If not it looks like you'll be fooling with the air conditioning computer seems like there's nothing else fuse switch blower motor all being fed by the AC ECU . Marvelous swap the cheap resistor for an expensive computer yikes
     
  4. ChapmanF

    ChapmanF Senior Member

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    In fairness, the computer does do a couple more things than the old resistor did.
     
  5. Tombukt2

    Tombukt2 Senior Member

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    Yes in our 15% of the air conditioning blows well cool and and good volumes so no issues other than when we couldn't initially get it to start when we change the engine just leaving it unplugged for a couple of days and then plugging it backed up at magically just said okay and it's been blowing us out of the car ever since which it did before we changed the motor. I guess a c e c u's could be fairly inexpensive especially junk ones.
     
  6. DJ Moore

    DJ Moore New Member

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    I took out the old motor and gave it a couple of knocks, cleaned it out some and just made sure everything was secure when I put it back together and it works like old for now. Still have a new motor coming tomorrow, so I'll just hang on to it for now. It was really easy to do.