Fan blade orientation?

Could some kind soul tell me which way the fan blades are oriented behind the radiator? Should the rounded (presumably leading) outside edges of the blades be toward the radiator, or away from it? Just ruling out a possible source of a cooling problem. Thanks!

 

Evidently it is possible to reverse them.

See:
http://priuschat.com/forums/prius-t...me-prius-overheating-normal-4.html#post610655

It looks very much like mine are both reversed. That would explain why the outside air temp seems to climb to unreasonable levels at the same time the A/C stops working, and the overheat warning comes on. The airflow is not correct.

I guess it's possible I'm just looking at them wrong, but they certainly look like their orientation is not correct.

 

Thanks for the reply. I PM'd you with a more detailed question, but I guess I'll throw it out here. Just wanted to make sure I understand that the pointy corners of the blade tips are on the trailing edges of the blades (like an airplane propeller). On my car, these are facing the radiator. That seems backwards, since the fans are behind the radiator.

Since the car only has 20,000 miles, I wouldn't think the brushes would be very worn yet. I tried to get the car into inspection mode, but didn't get anywhere with that. If I could get the fans to start, I could easily determine whether everything is correct--but it sure looks wrong right now.

The only reason the car isn't at the dealer right now is that I'm awaiting arrival of the new warranty paperwork. Wonder how quickly they would have sorted this out, though.

 

For whatever reason, they're on the wrong sides, and facing the wrong directions. The 7-blade fan is on the left, and the 5-blade is on the right. Should be the other way, as I observed on another 2006 model today. Since they spin in opposite directions, they are actually working against the natural airflow when the vehicle is in motion. The most difficult part of this is getting the whole fan assembly removed so I can move the fan blades around. Looks like the radiator hoses will have to come off. Hopefully the inverter hoses can stay put.

 

The fans do run--they were running when I shut it down a couple of days ago. However, they are blowing air in the opposite direction desired. The dealer said he'll be happy to do the work--but because I purchased the vehicle used, the warranty is still being transferred, and I may have a couple of weeks to wait. However, point taken regarding risks to the inverter and cooling system. I may indeed just pay the dealer to do the work, since I know exactly what repair is needed. Thanks for the inputs!

 

Both fan blades are now in their correct locations. I double-checked the part numbers, descriptions, and locations with a dealer. The 7-blade fan belongs on the right, and the 5-blade fan goes on the left, as you sit in the driver's seat. So, yes, they can be inadvertently reversed--either blade fits nicely on either motor, but they run in opposite directions. BTW, they were facing the correct direction, just turning the wrong way. I didn't have to remove any hoses or drain anything--it's just a tight squeeze reaching up to place the nuts. This wasn't such a difficult job after all. Thanks for all the inputs!

 

Patrick,
See my response below...

Rob,

• Do the two fan motors have the same part number?

No--and the prices are different. One turns clockwise, the other turns counter-clockwise.

• I take it that you personally swapped the fan blades? What does this procedure require? How hard is it to remove the blade from the motor?

Yes, I personally did the work.

1. Removed the plastic fairings/covers beneath the radiator (I also removed the inner wheel wells, as it seemed easier than separating the other pieces), and the plastic pieces on top, in front of the radiator.
2. Removed bolts retaining radiator, on top and bottom.
3. Removed a couple of electrical plugs to make it easier to maneuver the fan housing so as to make room to reach up between the radiator and the fan housing with a ratchet to reach the nuts on the fan blades.
4. Loosened fan blades with 8mm socket on 3/8" drive--a long drive handle made it easier.
5. The fan blades came right off.
6. Reverse procedure to reinstall fan blades. The keyway is identical on both motors, making it easy to inadvertently reverse their position.

• Did you need to swap the two fan motors; or did you leave the fan motors at their original locations?

I left the fan motors where they were. To have moved them would simply move the problem to different locations.

• When looking at the fans from the rear of the car facing forward, which direction is each fan supposed to turn (clockwise or counterclockwise?)

Left: clockwise; Right: counterclockwise.

I am also surprised that this problem did not manifest itself to the original owner. This seems to indicate that the car suffered front-end accident damage and the fans were incorrectly installed?

Yes, this is very likely the result of maintenance performed on the vehicle, rather than an assembly line error. I wonder if the previous owner sold it to me because he was stumped at the vehicle's strange behavior--he certainly made no mention of it when showing me the car. It was surprisingly tolerant of the backwards cooling arrangement. The primary manifestation was the intermittent air conditioning. I only saw a high temp warning once, and only for a few seconds. I have no idea why he didn't get it fixed, since it was under warranty. Maybe the dealer was stumped, too? Seems difficult to believe.