Is your fan running?

[modproductions]

I did connect directly to the fan motor, pass the wire through the firewall

But It's not running 100% of the time, by time to time, it stop. Specially when I' idleing witch make sens in accordance to the same repair guide :

Here is the testing procedure
"1. CHECK COOLING FAN SYSTEM
(a) Put the vehicle in the following conditions :
(1) The ignition switch is off.
(2) The coolant temperature is less than 95°C (203°F).
(3) The battery voltage is between 11 and 14 V .
(4) The A/C s witch is off.
(b) Connect the pickup of ac lamp-on ammeter over one of the two wires for the cooling fan motor.
(c) Turn the ignition switch to ON and wait for approximately 10 seconds . Check that the fan stops .
(d) Start the engine. Check that the fans tops with the engine idling."

And If I do it, it's true that the fan start with the engine and stop after 5-7 sec.
Then start after another 3-5 second stop after another 20
in cycle but not a clear cycle. It start and stop whenever it wants

[Cobb]

I had a newer scion xb that was like that. When you keyed on it reved the fans up, then it pulses them at idle. It wasnt like most cars that does nothing til a temp is passed, then run til the temp is 10-20 degrees cooler and stop. Or run on low for ax and if ac is on and the water temp surprasses a certain temp it goes to high speed.

To further confuse me was the fact that car always smelled like antifreeze leaking.

I guess you could wire up a manual relay kit for an aftermarket fan to your oems, however un plugging yours may result in a DTC.

Regardless, blocking the outside of your grill in my experience results in better mpg, even if you end up using the fans for cooling.

[toc]

Originally Posted by modproductions

I own a 2013 Toyota Matrix.
5 month ago, I did put one of those 12v light on my dash board to indicate if the fan is running. And surprise, the fan is running basicly all the time (95% of the time), even without the grill block.

I read about it and this is what is written in the toyota repare guide:
"The ECM calculates an appropriate cooling fan speed based on the engine coolant temperature, air conditioning switch condition, refrigerant pressure, engine speed, and vehicle speed and sends the signals to the cooling fan ECU to regulate the cooling fan. The cooling fan ECU controls the cooling fan speed based on the duty ratio signal sent from the ECM . By basing its control on the operating conditions , the ECM can control the fan speed optimally using the cooling fan ECU , achieving both high cooling performance and quietness . The cooling fan speed is determined based on the engine coolant temperature, air conditioner operating conditions , engine speed, and vehicle speed."

I'm not able to get what is the rimes or reasons, but the fan if basicly going all the time. Even when the engine is sub Zero cold in winter. Sometime it stop for a few second and start again. It ususaly stop when I'm ideling, but it's only stop for 3-4 second. Sometime with the grill block, the temperature may be as high as 97C (205F) and it stop for a few secs. That ECU make no sens.

My Mitsubishi had a similar type controller, except there was a recall on them. I couldn't get mine under recall as I was not the first owner.
So I built my own with relays and an arduino.
I could have used MOSFETs, by the engineer in me couldn't get my head past headsinking and so I decided a relay would do the trick with a 20 second timebase.
I saw an increase in fuel economy from it.

There's reasons they do run all the time though, including AC usage, plugged radiator etc. If it's ineffective in cooling, then it needs servicing.

[redpoint5]

Great tip.

I watch the engine temps on the UG, and when it reaches 215F, the temps suddenly plummet indicating the fans have engaged.

We're getting mid 80s in the Oregon valley these days, and my grill block has temps staying around 195F, which is about 10 degrees warmer than normal. I'll likely remove more of the blocking as temps rise.

[Miller88]

As soon as there is any air over the car, it will start spinning. It might even generate a bit of power.

I believe most vehicles have diodes to stop them from creating electricity and throwing things off - remember there are signals and communication happening. It could potentially cause issues.

Maybe the indicator doesn't use a diode? Or it's wired up wrong allowing the fan to back feed the car's electrical system?

[modproductions]

my light is a 12 volt bulb, not a led+resistor

[Jakins]

ahhhh, my radiator blew in the middle of the desert 500 miles from home because my fan switch stopped working! haha. ill probably do this mod

[Occasionally6]

Originally Posted by NoD~

The fan will kick on if you have the AC going. AC kicks on if you get defrost going... so you can have that fan kicking on summer/winter due to that as well.

That will help engine warm up (a bit) because the condenser is rejecting heat into the airflow ahead of the engine radiator.

If you have a PWM controlled fan, what is need is a duty cycle meter. A cheap way of getting that would be an adapted DMM but you could build something to do it.