M30B35 fan setup?

[mcbonio]

Just got a completed M30 project car, nicely done everything working as it should, fast.!

Only issue is the fan setup, its currently controlled via an on/off switch on the dash, I keep having to turn it on when the car temp is in the middle, then off when it drops to a quarter. Very annoying, I'm afraid I'll forget and it will overheat.

Is there anyway I can get some kind of temperature controlled switch that turns the electric fan on when the water reaches a certain level and turns off when its too cool? My wifes e46 318i has a setup like this.

The radiator has a fitting for a temperature sensor could I use this? If anyone could point me in the right direction to a kit or parts it'd be much appreciated.!

[zaust]

If you are using an e28 rad then tyre is a blank in the side of the rad you can fit a switch to or someone like demon tweeks will supply a universal one you can fit to your top hose.

[Bristol_Jer]

I've got a switch in my rad to control the fan, and an over-ride switch on the dash too just incase. My first e28 m535 rad didn't have the threaded holes to take the sensor, but the one I have now (new Nissens one) has 2.

I didn't wire it up myself, but I can take pics and make a wiring diagram for you based on mine if you like?

[mcbonio]

Yes please Jer, my radiator has a threaded hole for a temp sensor, so its possible.!

[Bristol_Jer]

The wiring diagram is the same as the second diagram Willnz posted in your tech help thread, I can take some pics tomorrow as well if you like?

[mcbonio]

Ok getting round to wiring this fan up over the next few days. I'm using a e28 rad which has a temp sensor already stuck in the side ready.

What switches are available to buy? At what water temp should the fan come on?

Bristol Jer, I'd love to see your setup. Could you be a total gent and take a few piccies for me?

Cheers guys, loving the M30 section. Many helpful folk.!

[mcbonio]

Seen this on deamon tweaks, looks good but not sure how I can wire this to use the temp sensor in my e38 radiator?

[zaust]

I need a switch or part number for the switch for the e28 rad. Anyone?

[mcbonio]

Is it a 91 degrees 2 pin radiator switch? 61 31 1 364 274



I'm think I follow you here Zaust, wire that temperature switch up to my fan via a fused relay.?

[walinsky]

For high and low speed switching I'm using both 61 31 1 364 272 and 61 31 1 364 273 (respectively 91 and 99CEL) as used in E28 535i.
Alternatively you could use the double temperature switch (91/99CEL) as used in E30's.

In your relay box there's 2 places reserved for relays already; and the printed circuit is ok. If your car came with air-conditioning they should be prewired already. If you (like I do) happen to own a non-aircon car you're SOL.
I decided to follow the e30 wiring diagram - so I ran 5 wires from the fuse box to the front of the car (1 feeding both temperature switches, 2 returning the signal from the temperature switches, and 2 (thicker ones) from the relays to the (spal 16") fan (the low speed one uses a standard .6 ohm resistor). Grounding the fan is easily done to chassis near the fan.
For the relay box you will be left with sourcing correct relays- and fuse-feet, and crimping 2 wires.
I'll be posting my progress on my project thread shortly, but - please do not wait for that glorious moment to happen - electrical schema's on this matter are no rocket science.

[leeparkes]

I was always under the impression the switch had to be the same temp as the thermostat? most M30 stats ive seen are 80 degree.

[mcbonio]

My fan is only one speed, and I don't fancy trying to get another one in now the engine is in.!

I think I'll keep it simple;

I'll get 91 degree switch "61 31 1 364 272" screw it into the side of my radiator and wire it to a relay which will open the fan circuit when the water in the rad reaches temperature. I'll have an override switch on the dash too.

Sound plausible?

[Rav335uk]

I have my temp switch on the thermostat housing in the cab, but i used a Ford part, not BMW, as it was a lower 80 degrees

[mcbonio]

What was the ford part number Rav?

[Rav335uk]

My mistake, i think it's a volvo part number

XEFS61 2 prong temp switch

[mcbonio]

you got that wired to your fan via a relay and 30amp fuse Rav?

[Rav335uk]

Yes mate, can't take pics as the car is in storage atm.

But works as it should.

[mcbonio]

Where you get the switch from? Can't seem to find a UK stockist.

[Rav335uk]

Try Matt ECP (Meatballs)

[mcbonio]

contacted him, they have none.!

[Rav335uk]

Try any motorfactors.
It was about £7 when i bought mine.

[walinsky]

I was always under the impression the switch had to be the same temp as the thermostat? most M30 stats ive seen are 80 degree.

Switches used on E28 M30s are 91 and 99CEL as mentioned before. E34 uses a double temperature switch (91/99CEL as well) 61 31 1 378 073 in combination with a 80CEL thermostat 11 53 1 713 040.
The thermostat on E28s is 80CEL as well; only has a different part number: 11 53 1 254 065

[walinsky]

My fan is only one speed, and I don't fancy trying to get another one in now the engine is in.!

I think I'll keep it simple;

I'll get 91 degree switch "61 31 1 364 272" screw it into the side of my radiator and wire it to a relay which will open the fan circuit when the water in the rad reaches temperature. I'll have an override switch on the dash too.

Sound plausible?

Sounds plausible.
As mentioned before there's space reserved in your fuse box already. Both high- and lowspeed relay sockets have printed circuits prepared already. From the top of my head the low-speed relay just needs to get signal from your switch. Then you'll only need to find a suitable spring-leaf contact for your (30A) fuse, and run 3 wires (back and forth).

[mcbonio]

Ok got all the parts purchased.! Will let you M30 crew know how it goes.

Cheers guys.! Always a big help.!

[mcbonio]

Going to wire this up tonight, anyone know where is a good source for a 12v ignition switched point in the engine bay?

[mcbonio]

So I don't use a switched supply I won't have any issues with the fan staying on as I switch the car off? Thats my only concern really.

[Rav335uk]

No, mine is wired up to stay on after the car is turned off, it stays on a few minutes. then goes off.

[johnl320]

No, mine is wired up to stay on after the car is turned off, it stays on a few minutes. then goes off.

mine too but rarely on in this weather at all

[mcbonio]

Happy days then.! Cheers fellas.

[jimbom30cab]

hwo did you get on with this mcbonio ? just wondered what you ended up doing and how it works? thanks

[mcbonio]

I got one of these, a 82c aux radiator fan switch. I ordered mine from a local factors for £14 as I couldn't find one online. It mounts in the side of my e34 radiator and is wired via a 30amp relay.

http://www.jbavarian.com/Auxiliary-Fan- ... B0087LADME

This is the wiring diagram I used, my fan is single speed so there is only a high speed circuit. I added an override circuit in the event of the components failing. I used a dash mounted air con switch for the override, this is annotated in red. It just bypasses all of the other components creating a direct connection to the battery, it's also fused.!



The fan comes on at half way and stops just after a quarter. It actually only ever comes on when waiting in traffic, driving around keeps the m30 quite cool actually.

[jimbom30cab]

Mr mcbonio sir,you are too clever for your own good, many thanks