Rep Power: 140

odd thing we noticed recently in this fun texas heat. it's 95+ degrees outside and humid. AC ON with Recirc OFF (just venting). When sitting in heavy traffic or at a red light after driving for a while, the engine temp will slowly crawl to about halfway if the Recirc button is OFF. Air also blows warmer while this happens. Turn Recirc ON and temp drops down, ac blows cold. AC fan is running in both conditions, not sure about radiator fan yet. Just don't know why Recirc cools the engine.

I went out earlier to check the fans and neither will run while idling in the driveway but the temp stays perfect. I have a large aluminum radiator so this may be the reason. Car is 100% stock other than that.

Any ideas here? I'm not sure how the AC logic works with these cars so maybe someone can help me figure it out.

 
Rep Power: 519

This is correct. Use recirc for best cooling and most efficient AC operation.

Job #1 of any AC system is to dry the air going through the evaporator. It can't cool well until the moisture is removed.....leaving it on fresh air causes the system to work extra hard to remove moisture, and gives poor cooling. Recirc lets the system cool the interior air that has already been dried.

On a hot day I roll down the windows and run the AC on fresh for the first couple minutes just to get some of the 180* heat out of the interior....then after it's rolling along and getting cooler I roll up the windows and switch over to recirc for max cooling.
It shouldn't make any difference other than the radiator fans are running ...Whenever the compressor is running both of the radiator fans should be running. Do they?


.....maybe you need to check the radiator coolant level and operation of both radiator fans.

Let it run long enough to turn on the radiator fans (without running the AC) and note the position of the needle on the temp gauge when the fans finally turn on, and again when they shut off.
Note: any breeze blowing through the radiator could keep it cooled enough that the fans wouldn't need to run for quite a while.

 
Rep Power: 140

Thanks for the info. Sounds like it's running somewhat normally except for my radiator fan operation. If both are definitely supposed to be running while the AC is on, I may have an issue with the main fan. The Condenser fan was running with AC on but not radiator fan so I guess I should check the fuse and relay, then check the fan motor by jumping the relay socket. Sound like a decent plan of attack?

 
Rep Power: 519

Absolutely, fix the inoperative fan.
Maybe prepare for the other fan to go bad in the near future too, it's just as old as the bad one.

Both of those fans are supposed to run at the same time, no matter which system is controlling them.

 
Rep Power: 140

Gotcha, looks like OEM style replacements are going for about 30-35 online. I'll diagnose the inoperative radiator fan and be prepared to replace. It could just be a relay though, so we'll see. Thanks for the tips and I'll update the thread when I check today or tomorrow.

 
Rep Power: 140

Found the failed component today. Radiator fan motor is shot. I swapped AC fan relay with Radiator fan Relay and AC fan still ran fine but radiator fan still did not. Then pulled the radiator fan relay and jumped the power posts, still nothing. confirmed method worked by testing on AC fan relay socket, worked fine. Look like I'll be grabbing a couple fans. Wondering if I should go with the OEM style or if there is a good inexpensive alternative that pulls a little more air.

 
Rep Power: 140

Also unplugged fans and swapped plugs, AC fan still worked. This eliminates the wiring between relay and fan as a possible cause and isolated the fan as the failed component.

Anyways, wondering if the $35 replacement fans (oem style) are as good as oem.

 
Rep Power: 519

Stock fan airflow was plenty adequate.

Fans are critical, I'd suggest quality over price

 
Rep Power: 140

all of the factory replacements are similarly priced except for the autozone, advance, oreilly's house brands, which i don't imagine are any better. Other than those, there is the Honda house but i haven't found anything online. Procivic is about the only good place i know of for parts and they didn't have OEM parts. Any other good places to check?

 
Rep Power: 519

Holy poop I just now got to check MSRP on those motors. Daaaayum they are proud of those. I see why the $35 model is appealing LOL

Passengers side fan motor brand says DENSO
Drivers side fan motor brand says MITSUBA
Maybe check the manufacturers websites for more research?

 
Rep Power: 140

I ended up buying a cheapie for the time being. $40 with a 10 year warranty so if it fails, or even lacks the ability to cool the car well, I'll send it back. I'll update the thread with a review when I receive and install it!

 
Rep Power: 140

Received new fan yesterday and bench tested it on a power supply. On 12v (lower than the charging voltage of the car), it seemed to pull a good amount of air. Rotating mass didn't seem perfectly balanced, but I doubt the OEM blade is either. I can always swap the OEM blade on to this motor/shroud if it's a concern. Construction seems similar in design/quality to the OEM part but the real concern is the life of the motor itself. With a 10yr warranty I figured it wouldn't be a big deal.

I'll be installing today and will update the thread afterward

 
Rep Power: 140

Update: Got home from work and the ol girl had almost finished installing the fan (cool to have a girl that likes cars). I let her go inside and wrapped up the installation. Everything functions as it should now. the fan pulls air really well and has a 10yr warranty so that's good. took a 200 mile trip with it with a good bit of traffic leaving houston and it kept everything cool. So far, a good purchase.