Battery fan gets no power

Ha, fooled you! See attached for how the fan looked before and after cleaning!

-Harry

 

No I meant the inside like wear that plug hangs the inside of that whole area I guess you cleaned it because it looks like it never had a speck of dust in there I don't mean the fan I just meant that where the plug is where the water was coming down and getting on the plug If I showed you that area in my car you can see where the hard water stains are still there. Etc your car looks pretty clean I guess you cleaned it or something.

 

Great work on resolution... I have a similar problem on my 07 prius... ecu won't turn hv battery bower on... but hybrid assistant app runs fan perfectly. App talks to ecu thru odb2 port ...so it is telling the ecu what to do...thus proving all wiring and relays are good and working. It's like the ecu doesn't have any software instructions on how to manage the fan.... any thoughts?
Thanks
Frank

 

Is the battery ecu setting codes for the fan or for high temperatures?

Some people think that Toyota's engineers run the battery "too hot". I don't hear the fan run on my 2006 until it hits speed 3 at around 125°F. That has worked fine for the original battery to go 14 years and 160k. I'm not going to mess with it.

If you want to run the fan all the time, go for it. Might gain some battery life (or not). Will shorten the fan life, so keep on top of that.



Posted via the PriusChat mobile app.

 

The contradiction in your words is that the ECU turns the fan on or off.

Blower Motor by MAX2 posted Mar 12, 2025 at 3:45 PM

But why the ECU decides to turn the fan on is another question.

 

Like other posters I never hear my fan running in North Carolina where it's 100° outside until I've been driving a few minutes and I pull up to a stoplight and I don't have the radio on and I'm paying attention I can hear it running on low and then if I'm really running the pee out of the car on a hot day and I pull up to a stoplight or in my driveway or at Walmart I can hear the fan running on higher speed is it on full blast I have no idea but the car is running all that The only time I can run it is when my bi-directional scanners plugged up and I call it up in the software but I'm not going to be doing that while I'm driving the car I'm going to allow the car to do its thing with the sensors and the wiring and all the crap that they put in the car Just because I don't hear it doesn't mean it doesn't work.? It just means it's not on and been called up I'm not a battery expert I don't know what these things should run at but I would think right around human body temperature wouldn't be too bad 96 to 120° somewhere you know I mean come on. Then you see other people wanting to wrap their battery packing dry ice or something to keep it cold I mean that seems a little excessive doesn't it.

 

What was the temperature of the hybrid battery when you used the hybrid assistant app to override the cooling fan?

I am not sure about the Gen 2, but my Gen 3 does not turn on the fan until the hybrid battery is higher than ~77F.