The Ultimate FDM (Fan Delete Mod) Thread

[blizzard424]

Yes, Amazon.

[Steve Pratel]

Yes, Amazon.

...

[ed323i]

I accidentally posted in a wrong thread. It ended up here (#2), don't know why.. Perhaps a mod can move it here?

[ed323i]

Hi, I think I've come up with an interesting electrical mod, that allows the temp switch to trigger the high speed fan directly, once the coolant reaches the lower temperature of the temp switch in the radiator.
If you use the official FDM mod and have installed the 80/88 temp switch and the 80 thermostat, this will cause the fan to immediately start at high speed at 80 degrees C bypassing the low speed fan altogether. It gives you even more wayroom/buffer because the cooling intensity is higher directly.

If you decide to leave the original 91 degrees C thermostat and the original 91/99 temp switch (which I'm doing now), then this electrical mod will cause the fan to start at high speed at 91 degrees.
I've done a first test and it seems to work fine. But I'll have to do some more tests on hotter days and in more extreme conditions.

Please check out all the background/theories and the mod details on this page: https://www.bimmerforums.com/forum/s...0#post30011050 .
It's a 15 minutes mod, which entails adding a wire bridge between pin #8 of the normal speed relay to pin #4 of the high speed relay (relay sockets are nicely labeled with the pin numbers), and sawing off pin 86 from the normal speed relay (or opening the relay and breaking the connection to pin 86 internally, or removing the wire from pin #8 of the low speed relay socket and connecting/adding it to pin #4 of the high speed relay socket for an invisible but way more labor intensive and original wiring harness modifying mod). That's all. Quite easy, and doable in 15 minutes.

I'll add the mod electrical diagram here:
add bridge high speed low speed relay.png

I hope a moderator can move that post here.. It somehow got stuck in the wrong thread..

[Midnighte36]

On the fan delete - for the lower temp switch whats the part number for the wiring harness end that you spliced into the wiring harness ? I cant seem to find it. People say its from a 318i but i dont have a part number. Thanks.

[RRSperry]

- 61 31 8 361 787 (up to 9/95) / 61 31 8 376 440 (9/95 and up) 80/88c Fan Switch,

[QUiKSR20]

Hello All - Tried to get as much details I could from this thread ( its 40+ pages ) without getting the " JUST SEARCH" response which I have done.. Can anyone just confirm this kit from FCP is all ill need to do this?
https://www.fcpeuro.com/products/bmw-fan-clutch-removal-kit-e36-early-hepu-e36fdmk2

Do I have to add an additional fan or just buy this kit?

Im in the process of a full coolant system rebuild ( all hoses and parts, not just the main two hoses ).

Thanks in advance, My car is a 95 OBD E36 325i if that makes any diff.

[spyderg0d]

Hello All - Tried to get as much details I could from this thread ( its 40+ pages ) without getting the " JUST SEARCH" response which I have done.. Can anyone just confirm this kit from FCP is all ill need to do this?
https://www.fcpeuro.com/products/bmw-fan-clutch-removal-kit-e36-early-hepu-e36fdmk2

Do I have to add an additional fan or just buy this kit?

Im in the process of a full coolant system rebuild ( all hoses and parts, not just the main two hoses ).

Thanks in advance, My car is a 95 OBD E36 325i if that makes any diff.

That kit doesnt have any fan at all in it.. Its just a waterpump, switch, thermostat and housing.

If your looking for an electric fan setup, you should look for electric fan kit, not fan delete kit.

[RRSperry]

Well to answer your question, Yes, that is the fan delete kit that will work with your 1995 OBD1 car.

Do you HAVE to buy another fan? No you don't HAVE too.. I haven't had a mechanical fan on my car in 15 or so years. I do check that the aux fan is working fairly often. (I figure that if the au fan comes on with the AC it's working...) I also have an actual water temp gauge and do not rely on the stock gauge that starts to move seconds before it's too late and you've overheated...

Somedays, I'm still tempted to re-install the stock fan and clutch. Sort of a belt and suspenders mindset...lol

But no, if your aux fan is working, you don't HAVE to have a mechanical fan.

[QUiKSR20]

Well to answer your question, Yes, that is the fan delete kit that will work with your 1995 OBD1 car.

Do you HAVE to buy another fan? No you don't HAVE too.. I haven't had a mechanical fan on my car in 15 or so years. I do check that the aux fan is working fairly often. (I figure that if the au fan comes on with the AC it's working...) I also have an actual water temp gauge and do not rely on the stock gauge that starts to move seconds before it's too late and you've overheated...

Somedays, I'm still tempted to re-install the stock fan and clutch. Sort of a belt and suspenders mindset...lol

But no, if your aux fan is working, you don't HAVE to have a mechanical fan.

Thanks guys, Sounds like for now ill just be keeping my fan... Just sparked my interest for a few while doing a coolant system full refresh.

[rbelton]

Before you try deleting the fan clutch, may as well do a proper test to see if your OEM fan clutch is actually bad:



link: https://youtu.be/fqnvOYwfxbU

[tranced]

Just did the electric fan conversion using the bimmerworld early model kit on my 1994 325i vert. The clutch fan was making a ticking noise heard within the cabin. It was starting to rub against the shroud upper exp. tank rad hose clip, which it cracked. Fan clutch and blades were basically new, and water pump had 30k miles on it. About 30K miles on the motor mounts. I read the convertible motor mounts are lower than the other models, so I'm guessing clearance as they wear is smaller.
I didn't notice any performance benefit from the clutch fan delete.

A few tips:
-You can leave the shroud on
-It is very difficult, but possible, to install the included pin style mounting ties without having to remove the entire radiator. It will still need to be unclipped from the bracket/frame support and moved what little it can while all the hoses are connected. I'm on the skinny side and was able to wedge my arms in enough to use a pry tool for leverage to push the locking disc onto the pin tie.
-You may need to jack the car up to install the lower mounting pin locking discs. There are rubber flaps between the shroud and the bottom of the radiator that you will push aside to get any tools or your hands between the two radiators.
-I grounded the fan on the 6mm screw that holds one side of some ac assembly mount to the chassis. It was the most readily accessible tap I could see. I sanded the chassis below the screw for the ground ring terminal and then spray painted over it all.
-On early models, the temperature switch low speed wiring color is black/green, as the OP stated.
-When changing the temperature switch, if you jack the car up on the side of the temperature switch no coolant will leak out of the radiator. I unscrewed the radiator cap before doing so.
-I previously installed an 88C thermostat, and with the e-fan connected to the temp. switch low speed wire, it engaged after I had gone on a half-hour highway romp, idling after parked. RPMs were pretty high the whole time. Ambient temp was 70F/21C.
-I used posi-tap connectors for all the splices (including inside the diag. port connector), and wrapped them in electrical tape. A bit bulky, but simple.
-I don't believe the relay mounting point acts as a ground. I zip-tied it near the engine bay's positive batt. terminal, where there are a bunch of holes and slots to use.