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View Full Version : viscous fan removed,need sustitute



Pagz
01-06-2006, 05:18 PM
Just realised i need the space between the radiator and engine for my bypass return...(and i dont want the viscous anyhow)...

After a short discusion with my local parts supplier,we thought it maybe a better choice to simply have the Dual fans come on at say ~85 degrees,and do away with any fan inside the bay...

theoretically this should work fine...from what iv seen,the current system is used to run the air-con,and as a backup if the engine reaches around 110.
i have only one temp sensor on my thermostat housing,so simply changing that to a different value will affect my cluster reading,and also my engine warm up etc

what i would like to know is:
-does the little black control box in the left front gaurd act as a relay+soft start system(because it seems to have a cast frame which is usually a heat sink)

if anyone has done this,can i simply install a switched thermostate
that can run in parallel to the current system and will simply switch the pilot wire to the "little black box"

also the weather is very mild here,so removing the viscous is no issue.


if anyone knows what im on about and can add some input please do...thanks...

Paul

Pagz
01-06-2006, 05:20 PM
lol why cant i add the "b"

jnenad16
01-06-2006, 06:05 PM
get a puller fan that has a rating of at least 2000 cfm, more would be even better. then all you need is one of these:
http://www.jegs.com/webapp/wcs/stores/servlet/CategoryDisplay?catalogId=10002&storeId=10001&categoryId=21529&parentCategoryId=11471&langId=-1
this is what I have on all of my cars, and it works flawlessly, just make sure you run it through the relay.

nenad

Pagz
01-06-2006, 06:15 PM
thanks nenad,
while at the parts supplier,i took a look at the original electric fan that is fitted to some model 202,which is what i will fit if the dual fan idea is insufficent.

instead of installing another relay,i would like it to switch the current relay system,which i believe is located in the left front gaurd from what i can see,also would like to know more about its exact function..ie does it restrict current for a few seconds until the fans ramp up...as this would help the high start up loads on the alt/electrics.

SLAMMED_C
01-06-2006, 08:38 PM
nenad: do you know of a system that uses a oem style temp sensor that I could drill and tap into the thermostat housing to control an aux fan as I would love to get rid of my viscous fan.. but I would just prefer a cleaner look with an oem type temp sensor as the coolant temp signal...

23k: the easiest way to run your set up would be to run the temp sensor seperate from your factory system..
are you looking for a cleaner install.. or just prefer to run it off existing relay and fan?

Ashkan's C280
01-06-2006, 09:09 PM
a lower thermo stat is would also work, and also try the cool harness mod, a friend of mine has done it and it works very well for himkind of wish I would have got that instead of the thing ned says, not that what he says is not good, just not oem, I have yet to install either the stat or the switch yet, how hard was the switch ned?or the stat, I can't seem where any of it is, granted I did not look to hard but where should i be looking?

jnenad16
01-06-2006, 10:53 PM
Originally posted by SLAMMED_C
nenad: do you know of a system that uses a oem style temp sensor that I could drill and tap into the thermostat housing to control an aux fan as I would love to get rid of my viscous fan.. but I would just prefer a cleaner look with an oem type temp sensor as the coolant temp signal...

the only thing I can think of right now would be the GM coolant sensor, I believe they have some that open at 170, 180, or 195 farenheit. check out www.jegs.com for these sensors.
infact, here is one I found:
http://www.jegs.com/webapp/wcs/stores/servlet/CategoryDisplay?catalogId=10002&storeId=10001&categoryId=23305&parentCategoryId=11471&langId=-1

nenad

Pagz
01-07-2006, 12:03 PM
Originally posted by SLAMMED_C


23k: the easiest way to run your set up would be to run the temp sensor seperate from your factory system..
are you looking for a cleaner install.. or just prefer to run it off existing relay and fan?

hey slammed,
Do you know the function of the little control box located in the left front wheel gaurd?...Is it just a relay,or is there more too it?

im planning to simply run a temp controlled circuit(from thermostat housing) in parallel with the same switch wire the ecu uses...

that sensor nenad posted could be ideal...

Or you could go bling... :D

http://www.hksusa.com/products/?id=1697

or this one uses the OEM sensor
http://www.takakaira.co.jp/asp/table.asp?id=1050&cat=2&prodid=JKkGhHhceDfbiEd

jnenad16
01-07-2006, 03:20 PM
Originally posted by 23K

Do you know the function of the little control box located in the left front wheel gaurd?...Is it just a relay,or is there more too it?
http://www.hksusa.com/products/?id=1697

or this one uses the OEM sensor
http://www.takakaira.co.jp/asp/table.asp?id=1050&cat=2&prodid=JKkGhHhceDfbiEd
are you refering to the junction box on top of the wheel well? that is just a positive cable, it has two sides, on is hot(the bigger nut) and the other is switched(the smaller nut). this is what I use for the power supply for my thermoswitch, then I route it through a relay.

nenad

Pagz
01-08-2006, 08:06 PM
Originally posted by jnenad16
are you refering to the junction box on top of the wheel well? that is just a positive cable, it has two sides, on is hot(the bigger nut) and the other is switched(the smaller nut). this is what I use for the power supply for my thermoswitch, then I route it through a relay.

nenad

the part im refering to is located in front of the front left wheel arch,you will need to remove the front plastic liner to see it...

jnenad16
01-08-2006, 08:58 PM
Originally posted by 23K
the part im refering to is located in front of the front left wheel arch,you will need to remove the front plastic liner to see it...
do you have a picture of it?

nenad

Pagz
01-08-2006, 10:16 PM
Originally posted by jnenad16
do you have a picture of it?

nenad

Im away from the car for the next week,but will grab a pic when im back....
It has maybe ~3 heavy cables,and ~2 fine cables entering it...which sounds like feeds for the fans and control wires for relays...

hopfully slammedc will dig up some info from his work;)

SLAMMED_C
01-10-2006, 07:16 PM
okay.. here is what I found....
that box found in the left front wheel area is n65/1.. or the aux fan control module.


Aux Fan Function:

"The aux fans (M4m1, M4m2) are switched on in relationship to the refrigerant pressure and/or coolant temp.
The pushbutton control module receives the refrigerant temp signal from the air conditioning coolant temp sensor and the refrigerant pressure from the refrigerant pressure sensor.
This input information is compared with the stored values by the pushbutton control module, The calculated output informationcontrols the relay for the aux fans, which switches on the aux fans either directly or over the aux fan preresistor (R15).



The following switching points are possible:

Refrigerant Pressure:
stage 1:
@ 16 bar (ON)
@ 13 (OFF).
stage 2:
@ 20 bar (ON)
@ 17 bar (OFF).

A/C coolant temp sensor:
stage 1:
100 degrees celcius (ON)
95 degrees celcius (OFF).
stage 2:
115 degrees celcius (ON)
107 degrees celcius (OFF).

Aux fan control (M4m1, M4m2):
stage 1:
9Volts.
stage 2:
12Volts.

NOTE: it is not possible to switch on aux fans in stage 1 at outdoor temps <+5 degrees celcius.




Aux Fans Control Module Function:

The pushbutton control unit transfers the input information ont the coolant temp and/or refrigerant pressure to the aux fan control module.
The aux fan control module compares these values with stored values and switches the aux fans (M4m1, M4m2) ON of OFF according to the condition listed in the table below.

Refrigerant Pressure:
stage 1:
@ 16 bar (ON)
@ 13 (OFF).
stage 2:
@ 20 bar (ON)
@ 17 bar (OFF).

A/C coolant temp sensor:
stage 1:
100 degrees celcius (ON)
95 degrees celcius (OFF).
stage 2:
115 degrees celcius (ON)
107 degrees celcius (OFF).

Aux fan control (M4m1, M4m2):
stage 1:
9Volts.
stage 2:
12Volts.

*same as above table*


Description of wiring diagram:
(note: if anyone wants the wiring diagram of the aux fan control module email me please)

N65/1 (aux fan control module)
Pin 1: 4.0 RDYE goes to F1 (fuse and relay box) then to x12/3 (terminal block [circuit 30])
Pin 2: 2.5 BKWH goes to x64/4 (dual aux fan connector [2 pole]) connector 1 pin 1 then to M4m1 (aux fan left) power side, then through ground side of M4m1 to pin 2 of x64/4. comes out of x64/4 connector 1 pin 2 as 2.5 BN and goes to W16/3 (ground [output ground- component campartment- left])
Pin 3: 2.5 BKWH goes to x64/4 connector 2 pin 1 then to M4m2 power side, then through groung side of M4m2 to connector 2 pin of x64/4. comes out of x64/4 connector 1 pin 2 as 2.5 BN to W16/3.
Pin 4: 4.0 BN goes to w16/3.
Pin 5: 0.75 BNWH goes to K40/2 (drivers side fuse and relay module) on connector M5 pin 7, then comes out of K40/2 at connector C4 pin 6 as 0.35 BNWH to N19 (a/c pushbutton control module) pin 19.

Basically the aux fan control module is the splitting point.

Pagz
01-10-2006, 07:52 PM
Kool thats good stuff man!!!,thanks...could you forward me the wiring diagrams??

Hmmm,i see it runs a "preresister",which must give the two stages 12 and 9 volt!...so the system doesnt run a soft start,just two set stages

i notice the two sensors that control the system are both on the A/C system...but dont the fans come on if engine water temps reach around 110 degrees?

omeyhomey
01-11-2006, 04:25 PM
Hey guys

You don't need any of that. A common trick used by the bmw guys is using slightly lower thermostat and auxilary fan switch and then u can remove the engine fan safely and gain a few extra HP AND keep temps at the same level or lower with no negative drawbacks. I recommend the "Cool Harness", thats the auxilary fan switch mod i did on the S32 project car.

Ashkan's C280
01-11-2006, 04:33 PM
or the fan switch nened uses, imma have tht installed soon

Pagz
01-11-2006, 05:15 PM
Originally posted by omeyhomey
Hey guys

You don't need any of that. A common trick used by the bmw guys is using slightly lower thermostat and auxilary fan switch and then u can remove the engine fan safely and gain a few extra HP AND keep temps at the same level or lower with no negative drawbacks. I recommend the "Cool Harness", thats the auxilary fan switch mod i did on the S32 project car.

i beleive this will work on only some of the 202,later models use only one temp sensor for everything...so changing it effects everything...

omeyhomey
01-11-2006, 06:52 PM
Originally posted by 23K
i beleive this will work on only some of the 202,later models use only one temp sensor for everything...so changing it effects everything...

it doesn't matter, this trick has been done for decades swapping over from different chassis and etc so it really doesnt matter, all the thermostats are the same size as others in the same marque car so you can pick and chose whatever temp you want. stock M104 is typically 87 degrees and I got the 80 degree one (ironically enough this is identically same temperatures as the BMWs as well i've done it to). Hope that helps.

Pagz
01-11-2006, 07:51 PM
Originally posted by omeyhomey
it doesn't matter, this trick has been done for decades swapping over from different chassis and etc so it really doesnt matter, all the thermostats are the same size as others in the same marque car so you can pick and chose whatever temp you want. stock M104 is typically 87 degrees and I got the 80 degree one (ironically enough this is identically same temperatures as the BMWs as well i've done it to). Hope that helps.

Hmmm,so by changing the thermocouple that is mounted on the thermostat housing to a different one will change the temperature the fans come in at?....if so the cluster gauge and also your warm up enrichment will be effected??

from what iv seen your idea would work(and my parts supplier suggested that also)but only on the 202's with two seperate temp sensors...

omeyhomey
01-11-2006, 08:04 PM
Originally posted by 23K
Hmmm,so by changing the thermocouple that is mounted on the thermostat housing to a different one will change the temperature the fans come in at?....if so the cluster gauge and also your warm up enrichment will be effected??

from what iv seen your idea would work(and my parts supplier suggested that also)but only on the 202's with two seperate temp sensors...

no no, changing the thermostat will change the temperature the thermostat opens, has nothing to do with the auxilary fan. The auxilary fan sensor switch is what controls the electric fans. yes the gauge reads lower, my temps never pass 87-90 ever again where as they used to hit 100-105 before.

I got my "Cool Harness" from this website...

http://pages.prodigy.net/jforgione/MB_S500.html

Best money i spent on the cooling system. Simple plug n play solution to any cooling problems. hope that helps.

Pagz
01-11-2006, 08:18 PM
Originally posted by omeyhomey
no no, changing the thermostat will change the temperature the thermostat opens, has nothing to do with the auxilary fan. The auxilary fan sensor switch is what controls the electric fans. yes the gauge reads lower, my temps never pass 87-90 ever again where as they used to hit 100-105 before.

I got my "Cool Harness" from this website...

http://pages.prodigy.net/jforgione/MB_S500.html

Best money i spent on the cooling system. Simple plug n play solution to any cooling problems. hope that helps.

this does look good!...but i dont have a four pin sensor,only a two,and its different to the version 1 that is shown??...
lol my cars a pain...i dont have OBD2 either

also it looks like this mod is a simple resister setup,which usually costs about .0003 cents,the resister shown has the colour codes on it too;)

jnenad16
01-11-2006, 09:27 PM
Originally posted by omeyhomey
Hey guys

You don't need any of that. A common trick used by the bmw guys is using slightly lower thermostat and auxilary fan switch and then u can remove the engine fan safely and gain a few extra HP AND keep temps at the same level or lower with no negative drawbacks. I recommend the "Cool Harness", thats the auxilary fan switch mod i did on the S32 project car.
I dont think thats safe. the temps will fluctuate constantly, thus decreasing the engine life.

nenad

omeyhomey
01-11-2006, 09:54 PM
Originally posted by jnenad16
I dont think thats safe. the temps will fluctuate constantly, thus decreasing the engine life.

nenad

its been done for decades, bmw's have been doing it for years, some in the 200K+ mile range, it wont have any negative effects, in fact it will increase engine life. Not to mention the more heat cycles an engine has been through the stronger the block gets (lot of racing teams look for old blocks to build racing engines b/c the old blocks are so hard from the thousands of heat cycles they have been through, its an old trick).

Pagz
01-11-2006, 09:55 PM
hmmm,think i may buy a fan controller and run a seperate system controlling the dual fans,if its too unstable then i'll purchase the big electric puller fan and run the fan control on that...that way i have full adjustment of temperature also.

edit:yes its far from the cheapest option...i gave up tring to save long ago:D

Paul

Pagz
01-12-2006, 09:25 AM
hey I emailed the guy who produces the cool harness,here's what he said...


"Paul,
I'm not familiar with your car. I thought that after '95 all of the "CTS"
sensors were 'four' pin.

If this sensor is a "fuel" sensor --or-- a combo of fuel and coolant, then
you do NOT want to add a resistor.

Regards . . . . Jim Forgione"

Ashkan's C280
01-12-2006, 10:18 AM
jeff removed this fan without any problems at all, he did not add a fan switch ot lower stat either.... doing both should make it perfectly fine, it would low enough where the fan should not have to turn on....

SLAMMED_C
01-15-2006, 12:03 PM
Originally posted by 23K
[B]Kool thats good stuff man!!!,thanks...could you forward me the wiring diagrams??

YOU HAVE MAIL!! hope you get them all!.. it was a big file.

Im pretty sure that the aux fans really are only for the air conditioning side to aid in cooling the rad...

SLAMMED_C
01-15-2006, 12:03 PM
.

Pagz
01-15-2006, 03:59 PM
Originally posted by SLAMMED_C
YOU HAVE MAIL!! hope you get them all!.. it was a big file.

Im pretty sure that the aux fans really are only for the air conditioning side to aid in cooling the rad...

yo,thanks....hmmm but hasnt turned up yet...should be delivered after 5 though(because of size)

yeh im still not sure if the dual push fans will be enough...will find out soon though!

PS finally got her into the fab shop yesturday...we decided to go with a full 3'' stainless exhaust from the turbo to C36 muff,and will eventually cut open the muff and mod to suit 3" for best flow(as its only 2.5 inside)...damn cant wait to get it all on:D