Electric cooling fan ?

[Templ8e30]

I read a post on the old zone back in September/October time about wiring an electric cooling fan into the existing relay box but cannot find it as the tech forum only goes back to November.

Seem to remember Ian332isport posted the procedure.

Need to get mine wired up ASAP, Viscous fan is driving me nuts.

Please help

Cheers,

Iain T

[tbmw]

i'd be interested in this info to

[Simon]

Try posting an FAO, Ian332isport sure is the daddy when it comes to E30 electrics.....actually he's the daddy when it comes to all things E30....except for removing the M-tech II kits!

[Jimbob]

This has cropped up a few times, most recently for me is seeing Demlotcrew's M42, and immediately the lack of viscous fan. What are the benefits and how much will I be looking at for this?

[Simon]

Jim, the fan will only run when needed if wired up correctly, so it will put less load on the engine, which in turn means more power, and it does make a difference..... I felt it on my 316i!
I bought a kit from a local rally specialist which cost me Ԛ£75, that included the fan all fittings and a copper temp switch, though you can get better thermostatic switches that mount into a coolant pipe.

[E30Adam]

How do you mount the switch into the coolant pipe Si? Do you have to drill a hole and silicone it in?

I'd be interested in doing this and wouldn't mind seeing a tech article on it... any volunteers

[Simon]

With the proper thermostatic switch it's just like an extnesion pipe with fittings either end to fit the coolant pipe over it, you have to cut into the coolant pipe, trim a little off it, then get an extra jubilee clip and clip inot the pipe where you've cut through, shouldn't get any problems with that type of switch.
The other type which is normally the cheaper type and usually supplied with an electric fan kit is a copper probe type thing that you just undo a coolant pipe and slip it inside and tighten it up again, I never had any problems with this type, but I've heard other people have had problems with them leaking.

[Dom]

The kind I've just looked at had something that attached to the fins on the radiator. No chance of leaking but probably less accurate

[E30Adam]

With the proper thermostatic switch it's just like an extnesion pipe with fittings either end to fit the coolant pipe over it, you have to cut into the coolant pipe, trim a little off it, then get an extra jubilee clip and clip inot the pipe where you've cut through, shouldn't get any problems with that type of switch.
The other type which is normally the cheaper type and usually supplied with an electric fan kit is a copper probe type thing that you just undo a coolant pipe and slip it inside and tighten it up again, I never had any problems with this type, but I've heard other people have had problems with them leaking.

I like the sound of the T-piece type setup, souds like a proper way of doing it. Where would you wire the sensor to, I think I'm definately going to do this mod now.

[Simon]

This is the best type of switch...

http://www.demon-tweeks.co.uk/catalogue ... E=GLOEFC25

But if you want to keep the stock looking type fitment then stick to the original sensor in the radiator, and use the wiring Ian advises.

[E30Adam]

Bloody hell, fifty quid for a variable resistor in a bit of tube!!!

Demon Thieves!

[Simon]

Bloody hell, fifty quid for a variable resistor in a bit of tube!!!

Demon Thieves!

I assume you're going to make your own then!?

Your bound to be able to find it somewhere else cheaper than that.

[Jhonno]

hmm if there is a tech article on this i'd be very interested!! the 316i needs all the help it can get

[E30Adam]

Bloody hell, fifty quid for a variable resistor in a bit of tube!!!

Demon Thieves!

I assume you're going to make your own then!?

Your bound to be able to find it somewhere else cheaper than that.

I might speak to Ian and find out how he did his. If they did a black plastic version I would have probably bought that but the chrome is a bit bling for my engine bay.

[Andy335Touring]

I like the DT switch because the switching temp is adjustable.

I have in the past forked out for a Kenlow fan but to be honest i don't think you need to.The fan thats working well for my M30 came from a pug 205 1.4ltr for 4 quid from my local scrappy,i got it as a tempary fix because i didn't think it would be man enough but it is.

I'll have to wait till the summer to see how it does cope but i'm fairly confidant it will be ok.

The fans that are supossed to be an easy fit is the RS turbo fan and an E30 air con fan,also the e30 m3 fan but thats going to be fairly expensive ?

[E30Adam]

Yeah I've heard the RST one is supposed to be pretty good, I might go for that!

So where do you wire the temp sensor then?

[Simon]

An easy way to convert to an electrc fan and it also makes a lot of sense, just buy an M3!

[Andy335Touring]

So where do you wire the temp sensor then?

Sorry this answers not going to be much use to you but mine is controled by my ECU that sends an earth signal to a relay that powers the fan.

[Gwynleym10]

O.k I have an electric fan originally for a Vectra but its a bosch part. Was new and cost me Ԛ£30 on ebay. Bargin i think. Made my own mounting (in front of the radiator)

Currently I have it operating by a switch its a rear demister switch but Ian swapped me a green one and lloks pretty neet! .

Its not as bad as you may think having to switch it on and off. I switch it on as i'm aproaching half way and off when i get down to a quater. Basicly i leave it on most of the time in traffic, but when i'm doing more than 40 don't need it. Just think how often you look at your temp guage, I know i do a lot.

picy of my lights!


Ian did send me a wiring diagram of how to wire it in using standard BMW temp sensore located in the radiator. It was pretty easy by thte looks of things, I'll have a look.

Think I might have to wire it up properly for when the girlfriend starts stealing my car...otherwise it'll be a "hot" engine!

[Brianmoooore]

On my recent M50 coversion I used a fan and thermo switch from an old 7 series in a scrapyard. Total cost Ԛ£2.
I fitted the fan by drilling a hole in the E30 front frame about half way up and bolting the standard rubber mounting block there. The other two mounting blocks were bolted to two small pieces of bent steel strip, these in turn being bolted to the bonnet hinge plate, and to the crossmember under the radiator area.
One spare E30 325 radiator I had around had a tapping for the thermo switch, so this rad was used. A small wiring loom was made up, fitted alomng the front and back yhe right hand inner wing to the fusebox. There was a small rubber nipple sticking out above where the existing wires come out of the box. The end was cut off this to allow the new loom into the box.
Inside the fusebox there is a choice of two fuses and relay positions you can use, ( one intended for the full speed setting and one intended for the slower). All that's required is a couple of terminals for the relay socket.

[jmc330i]

I might speak to Ian and find out how he did his.

I think Ian has the radiator mounted sensor.

[ian332isport]

Oi, you guys talking about me behing my back

I really need to do a Tech article on this one. Infact, this reminds me I need to send an e-mail to someone who asked about this ages ago

Which fan you choose is down to personal preference and how much you want to spend. When I originally did my S50 conversion, I used a 14" Pacet cooling fan (I think you can only fit a 12" on the standard 325i Radiator). This fan was only wired to be a single speed, and operated from a standard BMW temp switch mounted in the E36 M3 Evo radiator that I used in the conversion. This radiator already had the mounting hole for the sensor, so it was easy.

As part of the A/C install I'm currently doing, I have removed the Pacet fan, and fitted an E30 M3 cooling fan which is mounted as intended on the front of the A/C condenser rad. The E30 (M3 or otherwise) A/C fan is the same fan as used on the M3 that does not have A/C. BMW can supply the correct brackets to mount this fan without mods or drilling extra holes.

When Ste owned Karan's Sport, I fitted an RS Turbo fan to it. I made up some small 'L' brackets that bolted to the side of the cooling fan, and then mounted this directly to the front of the radiator using the Pacet 'quick mounts'. These are a bit like round zip ties. You poke them through the brackets on the fan, through the radiator fins, and then push a fixing plate on the engine side of the bit that pokes through the radiator. These are quick, easy and require no extra holes in the car.

Now to the wiring.

You first need to decide what temp sensor you are going to use. Obviously, the neatest option is to mount a BMW sensor in the side of the radiator. Unfortunately, not many standard E30 radiators have the hole for this. If your lucky (or have a non genuine radiator), you may have a blanking plug that can be removed, and a BMW sensor fitted in it's place. This is what I did on Karan's car. If you look at the side of an E30 radiator (325i anyway), you can see the moulded boss where the mounting hole would be. It may be possible to drill and tap a suitable hole (M14x1.5).

If you can't use the BMW switch mounted in the radiator, then you are going to need some sort of adaptor that mounts in the top or bottom radiator hose. The adjustable one mentioned above is nice, but as already stated, a bit expensive. You can also get an adaptor that just has a threaded hole in the side that will take any temp sensor you have (various threads available). Another possible option, is to modify the metal cooling pipe that runs across the front of an M20 engine. If you got one of these, and had a suitable mounting boss (M14x1.5 nut) welded to it, you could use a BMW sensor.

The wiring I use is just a copy of part of the BMW aux fan wiring. You just use half of the circuit for a single speed fan, or all of it for a double speed. In most cases, a single speed is all that's required. I have only changed mine to dual speed as I need it for the A/C operation. The E30 fuse box already has the correct spaces for the fuses and relays that need to be fitted. You just need to get the correct crimp terminals for the fuse box.

I get most of my wiring supplies (including the fuse box crimps) from here:

http://www.vehicle-wiring-products.co.u ... /home.html

You have three choices for fuse crimps (depending on the size of wire you are crimping).

30-851 - small wire
30-852 - medium wire
30-853 - big fat wire

I'm pretty sure you can get these from the dealer under these part numbers:

61 13 1 370 691 - small wire
61 13 1 370 692 - medium wire
61 13 1 370 693 - big fat wire

It's possible that the BMW parts will come with a length of wire already crimped - they seem to do this for some reason.

The relay crimps are:

FBL6 - small/medium wire
FBL66 - medium/fat wire

The relay crimps can probably be found at the dealer, but I can't easily find the correct part in the ETK. These crimps are actually nothing special, and can probably be found at Halfords etc. They are just regular (non insulated) female spade style crimps, but they must have the little latch to hold them in place.

The part number for the 80/88 degree switch that I used is:

61 31 8 361 787 - approx £25 from the dealer.

You will also need the plastic wiring connector that plugs into the radiator temp switch, and the electrical contacts that are used with it. You need the following parts from the dealer:

61 13 1 378 410 - You need one of these
61 13 0 007 441 - You will need two of these (or three if you want to go for a two speed fan)

The fuse box already has the correct 12v feeds etc, so you don't need to find power. There's two fuses needed for a single speed fan (F18 & F19), and 3 fuses for a dual speed (F3, F18 & F19). You will find that one side of the fuse already has an internal connection. You just need to add the wires that run from the outer end of each fuse.

Here's a description of how the circuit works, and how it's connected etc.

Power leaves the fuse box via fuse F19 and goes to the input side of the temp switch. The output side of the temp switch then returns (one wire for single speed - two wires for dual speed) to the fusebox and goes to the fan relays. Relay K1 is the low speed relay, and K6 is the high speed. The return wires go to relay terminal 86 (If you are wiring a single speed fan, you only need to use K6). Pin 85 of the relays needs to be connected to GND. You can just run a wire to any suitable GND point.

Once the wiring is installed as above, you will find that when the temp switch closes, you will get 12v leaving the fuse box (via F19), and returning to the relay which will close. If you have wired both the low and high speed, then the relays will switch at different temperatures. Initially the low speed, and then the high.

You now need to wire the output side of the relay to the fan. The high speed is on F18, and the low speed is F3. Just run a wire from these fuses down to the fan +ve wire. If you are going for a dual speed fan, you will need a low speed fan resistor to give the slower speed. This should already be present if you are using an E30 A/C or M3 electric fan.

What you basically end up with is both the high and low speed wires connecting to the same +ve fan wire. It's just that the low speed wire needs to pass through the resistor before it connects to the fan. The -ve side of the fan just connects to a suitable GND point. There's a good one just behind the passengers side headlamp assy.

Hopefully that makes some sort of sense. It would probably be clearer if you had the circuit diagram, but I don't currently have anywhere to host it. If any kind souls have a bit of spare space, then I could e-mail it.

Any questions, let me know.

Cheers,

Ian.

[Templ8e30]

Thanks for that Ian, much appreciated

I have a non original rad in my 320i and a Volvo 340 temp switch ready to go in the boss.

Cheers bud,

Iain T

[nwmlarge]

er silly question time

what do you do about the fan belt

sorry if its a silly noobie question

[E30Adam]

er silly question time

what do you do about the fan belt

sorry if its a silly noobie question

You just remove the fan and leave the pulley in place.

[ian332isport]

er silly question time

what do you do about the fan belt

sorry if its a silly noobie question

The fan belt needs to stay, as it also drives the water pump. All you need to do is remove the mechanical fan and it's viscous coupling from the front of the water pump pulley.

Ian.

[nwmlarge]

ok i wasn't sure if there was an alternative belt you could put inplace that was smaller as you don't need to run the fan

it would also reduce weight if you took out the extra pulley no?

[E30Adam]

it would also reduce weight if you took out the extra pulley no?

LOL, well yes it would reduce weight but it probably only weighs a few grams so would be pointless. You could drive without shoes to save weight too you know

[nwmlarge]

i do and i only wear shell suits rather than jeans

ok i feel enlightned now cheers

[Andy335Touring]

How about using the spare sensor hole in the thermostat housing for the coolant switch ?

It looks like its the same thread or at least the blanking plug is the same thread that Ian mentioned ?

[E30Adam]

How about using the spare sensor hole in the thermostat housing for the coolant switch ?

It looks like its the same thread or at least the blanking plug is the same thread that Ian mentioned ?

Bloody genius!

[Brianmoooore]

How about using the spare sensor hole in the thermostat housing for the coolant switch ?

Have resurrected this ancient thread (linked to in a current thread) to comment on this point.
You cannot fit the sensor here, because the temperature at this point is the running temp of the engine, determined by the water thermostat, and should remain constant.
If you placed the sensor here, it would either not switch on until the engine is already overheating, or, because of hysterisis in the sensor, wouldn't switch off again.
The purpose of the coolant in the radiator is as a dump for excess energy in the engine coolant, as determined by the thermostat, and must always be cooler than the water thermostat's operating temp.

[Andy335Touring]

Not too sure, it may be that the 'stat housing is different on the M30 compaired to the M20 ?

The M30 has three sensor holes close together in a row, one for the ECU, one for the dash and the third one thats normally blanked off is for a temp sensor for the cars that had electric throttle. It's this blanked off hole that i think i was on about to use for a thermo switch ?

My ECU has a switched earth out put to control a relay for the cooling fan, it takes it's temp feed from the same hole that the Motronic uses.

Sorry for the diddy picture it's the only one i could find at the mo

[suzie650]

Digging this thread out once again...

Looking at my fusebox to connect my "new old" e34 fan, (and apart from finding a burnt out earth on the C114/P3, see my new thread) I realised that K1 (low speed relay) already has a spade on pin 86, connecting into the circuit board... So where do I connect my low speed input from the thermoswitch to K1???
The car never had A/C or an electric fan during my ownership...

[Brianmoooore]

85 of K1 should already be earthed.
In an aircon system, K1 is switched on either by the thermo switch or directly by the aircon switch, and the wire you've found on 86 is probably the one to the switch. At the moment, it will end at the round connector to the heater loom.