Transmission Cooler Fan Wiring Tip - 2009 e93 335i.

matreyia

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I could not find any useful information on the subject so here is it for anyone who is trying to install an auxiliary electric cooler fan to a 2009 e93 335i. Using a single terminal Temperature Sending Unit:

1. follow wiring instructions from the fan to the temperature sending unit terminal.
2. The easy part is wiring the negative wire and the constant positive wire.
3. The time consuming voodoo part is wiring the remote wire to some place in the hood area... you can use the left headlight wiring harness - there is a BLACK WITH GREEN STRIPE wire that is the headlight turn on wire. NOT the green with black stripe wire.

The temperature sending unit has a positive terminal that sticks out. It will not have a negative terminal...however, the negative terminal itself is the body of the sensing unit. So what I did is wrap a wire around the body and screwed it onto the receptical of the hose where the temperature sending unit tip will make contact with. Then I attached the other end of that wire onto the car grounding bolt next to the power steering container.
images-1.jpg


Be advised, this black and green striped wire is only hot when the headlights are on or the auto mode. I tried the other green and black stripe wire which was supposed to be on when the ignition is on...but it did not work.

In order to test the sending unit, you must ground it, after all wires are hooked up as described above...then use a heat gun to heat the tip and when it to the set temperature, the fan should kick on. Make sure the ignition and lights are on.

Again, left headlight harness, Black wire green stripe. If anyone finds the true remote wire, then let us know. Otherwise, this is a less than ideal setup.

20170819_231244_resized.jpg
 
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matreyia

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You can see all those other wires with connectors are victims of the search.
 

doublespaces

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So this is the 'trigger' wire you're talking about? Do all fans/switches have a trigger/remote wire? I was about to buy a thermo switch but haven't gotten that far yet.
 

doublespaces

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I went with a small Mishimoto dual pass which should clear the brake duct. Just need to figure out where I can fit the fans and how to wire it up myself, can't foresee it being too difficult.
MMOC-DP-SBK_3_3.png
 

matreyia

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So this is the 'trigger' wire you're talking about? Do all fans/switches have a trigger/remote wire? I was about to buy a thermo switch but haven't gotten that far yet.

Trigger wire is on the relay connected to the thermal sending unit.
 

matreyia

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I just posted this link to ATF coolers with integrated fans and 175F thermal switches in another thread. You'd just need 12V positive and ground wires, I believe. So wouldn't something like this be simpler to install?
http://www.bmracing.com/products/70...i-tek-cooling-system-with-fan-590-cfm-rating/
View attachment 5285
There are many different versions. I am sure there are some with built in prewired thermo sensors that only have + - .

Mine is a setrab for various reasons. Had to buy seperate thermo.
 
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matreyia

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I went with a small Mishimoto dual pass which should clear the brake duct. Just need to figure out where I can fit the fans and how to wire it up myself, can't foresee it being too difficult.
View attachment 5291
That unit appears to be a hum dinger to install and fit due to the top hose connectors. Mine has side hose connectors.
 

Jeffman

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If I'm not mistaken the Mishimoto dual pass pictured above has side connectors:
IMG_2511.jpg
 

doublespaces

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I there is about 5.5-6.5" of clearance betwen the headlight and the brake duct, it will be tight but it should fit horizontally. I have a setrab series 6 also, but I'm intending on retaining the air duct for the cooler. Also, the way you have it mounted, do you have room for your foglight or a fan? As there is no ducting for that position.
 

Jeffman

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By "side" connectors, i meant the long side because that orientation in your pic won't fit in the fog light area.
Gotcha. Thanks.
Is the bottom connector the ATF inlet from the stock ATF radiator, via a 180F T-stat?
 

doublespaces

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No, the top connector is the inlet and the bottom is the outlet(back to trans) as it should be. Don't know if he has it inline with the stock heat exchanger, but I wouldn't think so.
 

matreyia

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This is my setup in order to get the temp sending unit to fit inline.

Female to female 8AN straight connector
Steel adapter 3/8 NPT to 8AN
TEE adapter all 8AN.
3/8 NPT temperature sending unit.

You MUST screw unit on the entire way done to "zero thread zone." Not as shown in this pic...here is not all the way in yet
20170823_190157.jpg
.
 

doublespaces

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View attachment 5325

SPAL puller fan. 5.2 inch.
I can't believe how ridiculously powerful this fan is. More than enough for the setrab.

I didn't think about mounting the exhaust vent this way, but why did you mount it with the vanes pointing up? Also, why did you cut out the vanes? And is your foglight installed still?
 

matreyia

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I didn't think about mounting the exhaust vent this way, but why did you mount it with the vanes pointing up? Also, why did you cut out the vanes? And is your foglight installed still?

1. Vent up because hot air rises. I figure this vents up makes the hot air escape easier than down.
2. Vents cut to allow for rear of fan to take up interior space.
3. Foglights do not fit with all hoses in the way in the front area.
4. Had to move SPAL fan and cooler more forward last might so the rear of the fan would stop hitting the front tire.
 

nate335i

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Good info! I will also be retrofitting an oil cooler to my PD transmission, once it arrives to Hawaii. I am currently looking at Setrab series 1, 19 row cooler (with 342cfm fan).. I plan to use the ducting in my 1m front bumper for the cooler, will fab my own brackets etc.. Ill be using the improved racing 165* high flow trans thermostat. I have the VS fittings and plan to find a compatible switch.
What are you guys using for the switch to turn on the fan? Not the wiring location, but the actual switch/sensor? and what temp is optimal for the fan to engage?