Electric Fan

[dbgeek]

I'm about to purchase and install a SPAL puller. Bimmerforums has conflicting info regarding size - from 'a 10in will work fine' to '16in or you blow up'. I was leaning toward the 16" straight blade 2300 cfm model.

 

Also, are you guys using an independent relay or splicing into the factory aux fan wiring (which is 2-speed)?

[Scany]

I removed all my fans and ran a couple of events with no problems, but then put my mechanical fan back since I don't have a temp sensor (except the stock one). Probably look into a SPAL later, but have no idea what.

[matt325]

I am using the SPAL 16" straight blade fan (30102120).

 

I spliced it into the factory relay, on the low temp side so it comes on sooner, when needed.

 

I also did the bimmerforums "fan delete" mod and changed the thermostat to 80 deg. C and the temperature switch to the 80/88 deg C.

 

I am in Florida, and it gets HOT at the track, and so far so good. The fan has come on about when I expect it too, usually in the pits after coming off the track and sitting for a bit before shutting the engine down.

[VaTechM3]

I have a 16" SPAL fan as well on mine. I have mine wired to a switch and turn it on during the cool down lap and when the car is sitting. I'm thinking about changing it over to the factory wiring so I don't have to worry about turning it on and off when I think it should be on...

 

I spent like $30 on the wiring kit from BW and wanted to get some use out of it first haha.

[dbgeek]

I ordered the 2300 cfm 16" SPAL fan and the 80/88C switch. They should be here in time for installation this weekend.

 

Matt325 - do you have any issue running the fan wired to the low temp side? BF.com mentioned that the low side turns off when the high side turns on - thus if you get too hot, the fan turns off.

 

Thread on BFC for this very question (says to wire both high and low to the hot side of the fan):

http://forums.bimmerforums.com/forum/showthread.php?t=1459150

 

For those of you that have removed the fan shroud, how are you supporting the expansion tank?

[matt325]

Matt325 - do you have any issue running the fan wired to the low temp side? BF.com mentioned that the low side turns off when the high side turns on - thus if you get too hot, the fan turns off.

 

Thread on BFC for this very question (says to wire both high and low to the hot side of the fan):

http://forums.bimmerforums.com/forum/showthread.php?t=1459150

 

I saw the post on BFC, and I didn't realize the low side shuts off when the high side turns on. Should have paid more attention to the wiring diagram. Is there a difference between the "high" and "low" side in terms of the voltage supplied to the fan? Does it run faster?

 

To date, when the fan comes on (and I have to sit there after coming off track for a bit to even do this), it runs for a few minutes and then shuts off. I believe that is has been able to cool the car down such that the high side doesn't need to come on. But I could be wrong, maybe it was just the low side shutting off? The car has not had a problem overheating.

 

What would be a scenario where the car needs to go to the high side? I would think that something has to be pretty wrong if you are getting past the low side temp enough to need the high side.

 

If it is as easy as just wiring both the high and low side to the +12V of the SPAL, I will probably do that just to avoid making my head hurt thinking about it.

[dbgeek]

From what I've read, the high and low sides are both 12VDC and the stock e-fan has a resistor pack (in the fan assembly) that makes the fan run slower when powered through the low side. So, with that in mind, I will simply crimp the high and low together and wire it to the new fan's positive wire (brown = ground, negative).

 

From other readings, the a/c button in the car will make the fan turn on in the slow speed, which would just be 'fan on' in my case. I will test after installation this weekend.

 

I will have both the 91/99C switch and 80/88C switch. Given that I only want the fan on when it gets warm, I may keep the stocker 91/99C.

[dbgeek]

Electric fan is installed and operating on the A/C button AND the radiator temp switch - I also finsihed the rust repair in the driver floor pan and installed the seat and harnesses.

 

I wired both the low and high Aux Fan +12 to the hot side, and the brown to the ground. The fan worked via the temp switch that way, but not the A/C button.

 

I had to short a connector that went to the A/C pressure sensor. There is a white 2-pin connector and a black 2-pin connector that connect to the A/C pressure switch, and they are found behind the pass headlight. Shorting the white connector makes the fan run all of the time. Shorting the black connector makes the fan operate via the A/C button, but ONLY when the interior blower is NOT OFF. Basically if the A/C button is lit, then the fan is running.

 

Corrent me if I'm wrong, but it seems to be working, so...

 

Next up: Transponder, Engine and Trans Mounts, Intake and Exhaust.

[Jon M.]

Electric fan is installed and operating on the A/C button AND the radiator temp switch - I also finsihed the rust repair in the driver floor pan and installed the seat and harnesses.

 

I wired both the low and high Aux Fan +12 to the hot side, and the brown to the ground. The fan worked via the temp switch that way, but not the A/C button.

 

I had to short a connector that went to the A/C pressure sensor. There is a white 2-pin connector and a black 2-pin connector that connect to the A/C pressure switch, and they are found behind the pass headlight. Shorting the white connector makes the fan run all of the time. Shorting the black connector makes the fan operate via the A/C button, but ONLY when the interior blower is NOT OFF. Basically if the A/C button is lit, then the fan is running.

 

Corrent me if I'm wrong, but it seems to be working, so...

 

Next up: Transponder, Engine and Trans Mounts, Intake and Exhaust.

 

Great work, knocking on wood, but it is starting to look good for July!!!!

[dbgeek]

I want to clarify that the radiator temperature switch operates the e-fan regardless of the position of the interior switches. The A/C button will only operate the e-fan when the interio fan control knob is not in the OFF position.

 

Pretty happy with this mod.

 

Transponder installed, cleaning passenger floor pan.