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AC fan and radiator fan question, very informative

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RayBan GST

RayBan GST

15+ Year Contributor
665
4
Oct 21, 2007
DUBAI UAE, Asia
can you please share some information about the AC fan speeds? how does it speed up and when? my ac is always on but i never seen the fan on high speed. when it should be on high ?

also one more question , i have connected the two fans ( ac and radiator) so they can kick together and off together and they seem to work perfectly ,however i have connected them as follows on the picture below

the last relay on the right ( lo ac fan) with relay number 4 which is ( rad fan lo) that is under the (tail lamp) they both kick well now but is this the right way or shall i connect number 2 and number 5 relays as per the vfaqs?? if you tried the vfaq way can you share if your ac fan kicks on HIGH when the ac is on?

thanks
 

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OK, First of all.
Your AC Fan will never turn ON (Hi) when you use the AC, It will turn ON only the Lo, The AC (Hi) fan will turn ON only when your car overheat, so basically, the High speed AC fan purpose, is for the engine cooling and not for the AC.

Your car doesn't overheat, that's why, your AC fan (HI) doesn't turn ON.

The way you have it now, is not turning the AC (HI) fan, it is turning ON only the Lo AC and the cooling fan (radiator), they both turns ON at the same time, when the cooling fan turns ON, the AC Lo will turn ON as well, and when the AC Lo fan turns ON, the cooling fan will turn ON as well.

Now, If you want the Hi AC Fan to turn On only when the AC is ON, then you have to swap the lines from the Hi AC to the Lo AC, Just swap the wires at the Fan connector or at the fuse box.

I would say, you are fine the way you have it, The AC (Hi) doesn't turn ON, but you have the cooling fan turn ON instead, which it will be the same as if the AC Hi is ON (you will get the same air or more from both fans).

Hope you understand what I'm trying to say.

Edit,
I forgot to ask, Are you Manual or Automatic?.

Manual uses only 4 relays which Automatics uses 5 relays.
 
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thanks for the nice reply, its manual.

Ok now the way i have it is as follows. ac on , both fans on but the ac fan is on low and rad fan is on high, the problem here is when i reach 210 degrees the ac fan never on high. It will just stay the same. Now i changed to the vfaq way and when the ac is on ac fan is on high and rad fan is low, but when i reach 210 degrees they will both kick in at high speed? Or its the same? I tried to overheat it to try but it doesnot want to overheat just want to know ###. Im now on the vfaq way but i can change so which one is better ? Today it was 49 degrees with 79 humidity its hell on earth here in dubai and i need this mod to cool down the system a bit.

Thx.
 
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Well, to be honest, I have never seen the vfaq, I know this from hand, I redid all my wiring, so I know how it works, If you can link me to the vfaq so I can see how you did it.,
well, I will search for it and once I see how you did it, I will post back.

Is this how you did it (under electrical 2g T)?.
Visual Frequently Answered Questions - Home Page
 
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yes thats the way but without the switch to keep them on all the time and control them, i just connected relay 5 and 2 together with one wire as per diagram so they can be on together and off together only.
 
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Have you try it like that?, Does it turns ON?.
The way you have it now (2 and 5) it came wired like that from factory.
Do you have a chilton or manual so you can see how the diagram is?.

Well, let me explain you.
The ECU has two lines, one for the LOW cooling fan and one for the HIGH Cooling fan, The Low Line is wired to the Low cooling fan only, when the engine cooling gets to its target, the Low cooling fan will turn ON, But If the car overheat or gets hotter then the normal cooling temperature, the High Line from the ECU will trigger the High cooling fan and the High AC Fan., So basically, Both High Cooling fan and High AC fan are wired together and will turn ON ONLY WHEN IT GETS HOTTER THEN NORMAL OR OVERHEAT.
So saying that, the #2 and #5 Sensors are wired together from factory, so you don't need to wired them like you did it, the vfaq have wired with a switch to turn both High fans at any time you want, But it requires the switch inside the cabin.
Now, at this point, I am confused on what exactly you want, I know you said you want both fans to turn ON, But do you want them to turn ON via AC, or via Cooling (Radiator)?.
If you want to turn both fans when temperature get its target, then its very easy, Just swap the lines from the ECU (low cooling line with Hi cooling line) and you are set, this way, when the temperature get its target, both Hi fans will turn ON at the same time.,, I have mine like that and it works like a champ with my 2 little slim fans (10" pusher).

Let me know if you get confused or didn't understand something so I can explain a little different.
 
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thank you again what i want is to run both fans on HIGH when the ac is on and also when the tempreture gets to target when the ac is off for example

what can i do to make both fans on high when the ac is on and also when the tempreture reaches the limits when the ac is off.

can you please tell me which relays on the picture i posted , maybe its so simple on the picture to tell me which relays shall i connect together to get both fans on HIGH when the ac is on and also as i explained above.


thanks
 
Upvote0
Miguelmcv sounds like he has aftermarket 2 wire fans (and/or has added them to the stock relays).

If you have the two stock 4 wire fans they operate quite differently and are more complicated. The speeds are not obtained by voltage on a unique specific wire but rather voltage on wire combinations. See here for explaination: http://www.dsmtuners.com/forums/new...-issue-plus-wiring-them-up.html#post151311484.

As for what speeds the stock fans turn on at and when, see: http://www.dsmtuners.com/forums/attachment.php?attachmentid=86862&d=1219990229. As you can see the ac fan (condenser fan) will never go on high without the ac on. But with ac on it will go on high if the temp gets high enough (along with the radiator fan on high). Of course if you don't use ac or it's broken or disconnected, your ac fan will never go on high.

Since it is so hot in your country I recommend one simple mod. Just jumper the ac fan blue-white wire (or blue-black if using the fan side of the connector - one that actually goes into the fan motor) to the ac fan blue wire (or blue if using the fan side of the connector - one that actually goes into the fan motor). Leave both wires connected to the fan when you do this. Then when either ac relay goes on (hi or lo) the ac fan will go on high (and you don't even have to have working ac). The ac relays will be able to handle the extra current. The wires from the ac relays should technically be a larger gauge for this but it should work without burning them up (one may get a little warm when only one relay is on).

Of course if you have working ac and fan relays wired stock, you shouldn't need to do anything provided you use the ac. But if you don't use or have working ac, the above mod should work to keep both fans on high.

[The reason I suggested this mod instead of turning both ac relays on together is because one (hi) is activated by supplying a ground while the other (lo) is activated by supplying +12v. So you can't really turn them both on easily - it would take some messy wiring.]
 
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thank you very much , just one simple quesiton now , shall i just go back to my previous conneciton wiring as per my first post ? becasue with this mod i can see maximum 95 degrees on my after market temp gauge wired from the upper radiator and today when i did the Vfaq way i can see its 98 and also 99 degrees and almost 100 :)

from your exeperience is it ok if i wire like my first post ( is there any harm to burn the relays) ?

the last relay on the right ( lo ac fan) with relay number 4 which is ( rad fan lo) that is under the (tail lamp)

thanks
 
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just my first post up here with the picture of the fuse box

the last relay on the right ( lo ac fan) with relay number 4 which is ( rad fan lo) that is under the (tail lamp) i connected them with one wire only.
 
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ok here is a drawing , its the first form the right LO AC with the 3 from the right or the 4th form the left ( same) LO AC with LO rad


hope its clear
 

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So it looks like you connected together pin 4 from both relays - white-black wire from radiator Lo to blue wire from ac Lo? This will cause the ac fan to go on high when both the radiator Lo and ac high relays activate. [This is the rows in the "fan operating mode" of http://www.dsmtuners.com/forums/attachment.php?attachmentid=86862&d=1219990229 wherever I have a hand written "20,21" under the hand written "ECU pin lo". This will then change the 3 medium speeds of the ac fan in the ac switch off section to be high speed.]

This looks like a good mod that will get you want you want. Just make sure you used a large enough wire (13 gauge or larger - {AWG number 13 or less}). Then you don't need my mod.

I'm going to bed - it's 5:30AM here.
 
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Thanks for all the info

we have around 30 cars all from Japan here in UAE, around 20 Autos and 10 manual and i owned 3 of them and sold them off and now i bought one manual back again.

parts are pain here almost impossible to find parts , i am in need of head lights and cant find anywhere if you have i am intrested :| . i always order parts from ebay if i find but once the engine or transmission is gone on these cars in uae this means the car is going to the scrap. its fact nobody will bother to order or ship big parts for such an old car
 
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Spanky_DSM said:
i have a spare AC Fan and was wondering if i could replace the Engine fan on the passenger side with it.. since its slimmer..
Click to expand...

Yes you can it will plug up like factory, the fan needs a small spacer for one of the mounting brackets. but everything else lines up pretty good you have to trim around the radiator hose a little also.
 
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luv2rallye said:
Miguelmcv sounds like he has aftermarket 2 wire fans (and/or has added them to the stock relays).

If you have the two stock 4 wire fans they operate quite differently and are more complicated. The speeds are not obtained by voltage on a unique specific wire but rather voltage on wire combinations. See here for explaination: http://www.dsmtuners.com/forums/new...-issue-plus-wiring-them-up.html#post151311484.

As for what speeds the stock fans turn on at and when, see: http://www.dsmtuners.com/forums/attachment.php?attachmentid=86862&d=1219990229. As you can see the ac fan (condenser fan) will never go on high without the ac on. But with ac on it will go on high if the temp gets high enough (along with the radiator fan on high). Of course if you don't use ac or it's broken or disconnected, your ac fan will never go on high.

Since it is so hot in your country I recommend one simple mod. Just jumper the ac fan blue-white wire (or blue-black if using the fan side of the connector - one that actually goes into the fan motor) to the ac fan blue wire (or blue if using the fan side of the connector - one that actually goes into the fan motor). Leave both wires connected to the fan when you do this. Then when either ac relay goes on (hi or lo) the ac fan will go on high (and you don't even have to have working ac). The ac relays will be able to handle the extra current. The wires from the ac relays should technically be a larger gauge for this but it should work without burning them up (one may get a little warm when only one relay is on).

Of course if you have working ac and fan relays wired stock, you shouldn't need to do anything provided you use the ac. But if you don't use or have working ac, the above mod should work to keep both fans on high.

[The reason I suggested this mod instead of turning both ac relays on together is because one (hi) is activated by supplying a ground while the other (lo) is activated by supplying +12v. So you can't really turn them both on easily - it would take some messy wiring.]
Click to expand...


hey i saw ur a little familiar with wiring the a/c fans. i was wondering if u can help me wire the Ac and the cooling fan to operate on high when they active. like what wires to jump for them to work only on high when they come on. its 108 plus here in texas and the factory low setting is not cutting it. i have both the stock cooling and ac fans. no aftermarket fans.
 
Upvote0
Post #8, of Gary's, is a very good post on this, you might backup and re-read that. :thumb:
 
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