How to make a car heater blower motor fan turn in the opposite direction

[Brian L]

2009 Lexus IS350 blower motor turns in the wrong direction and sucks air instead of blowing air out of my vents. I am trying to figure a way to make the fan spin the other way. I live on a small island and getting a new blower motor imported would take about 2 - 3 months to get here right now with the pandemic.

• I bought the car with no blower motor - (yes, owner told me)
• I found a used one and installed it - I could hear it working, but no air was blowing out my vents
  
• I just figured out today the blower motor I bought (used) is from a Japanese right hand model. (There are tons of RHD ones on the island). My car is a left hand drive model. Both blower motors look the same - well almost, the wiring are on the opposite sided..
  
• I tried reversing the pos + neg wires but that didn’t work - just sparked and burning smell, but luckily the blower motor still works.
  
• I have another blower motor from another car that I was able to try - and this one I can reverse the wires to make it spin in the opposite direction - which does make the air blow out my vents. So I think this could work if I can only figure out how to do it on the blower motor I just bought.

Any ideas or suggestions?

below is an image I got from Ebay for a left hand drive model - I can also take the top off of mine and reveal the inside
Or maybe I can find the wiring diagram for the car or this circuit... if any of that helps.

Any help is appreciated!!

 

[littlespark]

If swapping over the pos and neg doesn’t work, there must be a diode or some other crafty electronics preventing it.

you’ll just have to get the right blower for your vehicle.

I don’t suppose there’s a way to mount the blower the other way round?

 

[PEG]

Hi,how many wires are in the multi-plug? Is this where you swapped them over?

 

[Brian L]

If swapping over the pos and neg doesn’t work, there must be a diode or some other crafty electronics preventing it.

you’ll just have to get the right blower for your vehicle.

I don’t suppose there’s a way to mount the blower the other way round?

I am trying to find a temporary 2 or 3 month solution until I can get one shipped to the island. And no, there is no other way to install it to get the fan to spin in the other direction.
[automerge]1598734437[/automerge]

Hi,how many wires are in the multi-plug? Is this where you swapped them over?

That image is from Ebay. Mine doesn't have a wiring harness. But yes, there are 3 wires. A 12 volt + (Blue) / A ground (White/blk) / Small white center wire is a signal wire. And yes, that is where I tried the polarity swap.

Thanks!

 

[PEG]

Hi,if the small wire is indeed a signal wire,then swapping the ground/power,should reverse the fans DOT. The only problem may be any damage caused during the previous swapping.
You could probably test the fan using a spare battery and two wires,just ensure a fuse of some sort,10A maybe,to limit another BBQ

 

[Brian L]

Hi,if the small wire is indeed a signal wire,then swapping the ground/power,should reverse the fans DOT. The only problem may be any damage caused during the previous swapping.
You could probably test the fan using a spare battery and two wires,just ensure a fuse of some sort,10A maybe,to limit another BBQ

Not sure I am understanding what you are saying - you said - "if the small wire is indeed a signal wire,then swapping the ground/power,should reverse the fans DOT." - Yes, the small wire is a signal wire - and yes, I did already try swapping the Power / Ground and it didn't work. What are you suggesting I do differently? Are you suggesting I try swapping the wires but without the signal wire connected?

 

[PEG]

Hi,if that signal wire,is a signal wire,and nothing else,the only two wires left,are the power and ground wires. In a normal fan motor,swapping these wires,would reverse the direction of your motor.
The only two reasons for this not to occur,would be either some other electrical or mechanical anti-reverse features,like a sprag clutch.....or you fried the thing,during your first trial.