lghtngyello03

iTrader: (44)

Alright, I took my car (03 Evo 72k miles) to the dyno Saturday for a dual map tune. When running the E85 out, my tuner noticed the car was getting warm (went from 203* to 213*) so he started looking at the cooling fans.

The main cooling fan runs like it is supposed to, but he noticed that the fan in front of the a/c condenser was not running. He tried to turn the A/C condenser fan on in Evoscan, but it wouldn't turn on. It will not run when the A/C compressor is running either. This fan has always worked before, as I remember being out of the car with the A/C running and seeing/hearing this fan run before.

So, yesterday I looked at all of the relays in the fuse box under the hood, all are functioning correctly. I checked them the way the manual says to check them, all are under 2ohms when tested, and you can feel them click. I even took the bumper off and used a jumper wire to make the A/C condenser fan run....so it isn't broken.

However. I have an 03, but I have an 05 repair manual...got it off of the forum for the mechanical stuff out of it. The 05 repair manual says that there is supposed to be 12v on 2 pins in the fuse box for the high and low speed relay for the A/C condenser fan. I am only getting 12v on one pin. But, when you plug the relays in to the high/low speed relay terminals in the fuse box and turn the key on, you can feel the relays click....so they are getting power with the key on.

I also checked for voltage on the power wire for the A/C condenser cooling fan plug. I am NOT getting any voltage here at all with the key on. Chased the harness from the plugs back to where it runs into the harness at the main cooling fan module, and it has no cuts on the harness. I ran out of time and patience to try to figure out how to test the main cooling fan module, as it was 97* here yesterday and I was pissed, lol.

I did a lot of looking here on the forum last night after I gave up, and found a post that says the 03s have a different way of running the cooling fans, that they don't use the hi/low speed relays?? See post #5 https://www.evolutionm.net/forums/ev...-question.html

Is this so? Does anyone know if the big cooling fan module (black box on the main fan) controls the A/C condenser fan on an 03 as well? I saw that the modules were a big problem once before, and I don't know if mine ever got replaced. Also is the A/C condenser fan a secondary cooling fan set to come on when the car reaches a certain temp, or just supposed to come on when the A/C is on?

Any help would be greatly appreciated... I want to drive my car now that I have it fixed and retuned, but don't want it to overheat after all my hard work done to get to this point.


Thanks,
Scott

lghtngyello03

iTrader: (44)

Bumping for some info and an update....last night I checked the fan control module per the factory repair manual.

The manual states voltage should fluctuate between 6v-14v with the car running and the A/C on....my module does not. My voltage stayed at a constant 13.12v with the car idling and the A/C running. The main cooling fan does kick on when the A/C is turned on, but the A/C condenser fan still will not.

Can anyone tell me if the fan control module has any control over the A/C condenser fan on an 03 Evo?

gsrboi80

iTrader: (38)

Nope. Haven't had an inner fan in over 7 years. Fan Control Module has long since been discarded

AC Condenser fan still works as needed or with AC on

lghtngyello03

iTrader: (44)

Thanks for the reply....anyone ever had an issue with the A/C Condenser fan not working like it is supposed to? All relays are properly functioning. I've read something about a temp sensor somewhere on the radiator? Does this control the A/C fan?

barneyb

There is no temperature sensor on the radiator.

The condenser fan is two speed. There is a relay for each speed. High speed is fuse 25 in the relay box. Low speed is fuse 11, both 30 amp. Both relays are controlled by the ECU.

lghtngyello03

iTrader: (44)

Both relays tested good and both have power to the relay pins in the fuse box.

Fan also can be jumped and it will work.

Car has never been in an accident..so no pinched wires.

barneyb

The fan has two pins where power is applied - must be two windings. Did you jump to both pins?

lghtngyello03

iTrader: (44)

The black plug has 2 pins..power correct? The gray has one pin. Ground? If I jump one pin on the black plug, either side, it runs..if I connect both sides of the black..nothing happens. So I guess I was wrong huh?

One speed must be burnt out?

barneyb

I don't know what the internals of the fan are. The service manual says to put power to one pin and then do the other. If the fan runs during both tests the fan is okay according to the manual. It does not say to energize both. And yes the other plug is ground.

So, I'm thinking, if the relays are working (clicking doesn't mean working - burnt contacts), the fan tests okay and you said it does, then there has to be a fault with the wiring. I've seen some crazy things inside underhood relay boxes.

lghtngyello03

iTrader: (44)

I checked the ohms per the manual, and both were under 2ohms. Also, for confirmation I took the high and low speed relays and put them in the horn spot...and the horn still worked.

Fan worked for the 9 years that I've had the car..it's not a daily. I've put 12k on it in 9 years. Fuse box is all stock as the car was stock when I bought it.

I looked in the relay box as well.

The biggest thing puzzling me is why is the cooling fan module checking a constant 13.12v with the air running, when the repair manual says it should fluctuate between 6-14v? The repair manual states this is a bad module. But my main fan runs when it's supposed a/c on or a/c off.

Alduin

I'm having a slight issue with this fan as well... And by slight I mean my magnets exploded inside the motor unit, causing the fan to self destruct. What a fun noise that makes by the way. Vibrated so much it shook the frame... Thought the crank was leaving the engine.

Anyway, I mistakenly thought this fan was connected to the radiator and not the AC, so I bought a mishimoto slim fan to replace it as I didn't want to spend oem prices... Long story short I'm having a hard time figuring out the extra gray plug wire.

I actually popped open the old motor to see what was going on in there and have a pic if that helps someone figure this out.

I'm assuming, I can splice the black and blue wires together, keeping red as the negative wire, and then splicing those together with the two wires on the mishimoto fan. If anyone knows this is a bad idea, please please let me know. I have a week or so before I attempt this.

In the picture, you can see the mystery black wire (gray plug) forms a different circuit than the blue/red. My friend and I believe this is a speed thing, high/low.

So if I connect the black/blue together, Im hoping I don't fry anything, as I believe the mishimoto fan is single speed anyway