Electric cooling fan ?

[suzie650]

Hum.
I assumed that the relay used in this position was the same as the other orange ones.
If it is, then it's definitely terminal 85 that needs a new spade connected (vacant at the moment) and terminal 86 that goes to the circuit board (no wire to be seen but you can see the soldering on the reverse of the board.).

By heater loom connector, do you mean the white/transparent 5 pin connector inside the fusebox meant to connect the (dealer retrofit?) A/C? I already found that the +ve for the thermoswitch (from F19) had to be taken from there, but I'm not sure if I checked continuity between one of the remaining 4 wires and K1/86. Will check tomorrow first thing.

By the way, as I didn't research on here first, I did undo the torx screw... good job the battery was disconnected! Could have done some damage otherwise What a stupid idea to connect it like that!

[suzie650]

EDIT:
Right, had another look today and found the problem.

K6/30&87 are internally connected, terminals 86 and 85 do not have spades in at the moment and will recieve +ve from the thermoswitch for 86 and -ve joined to the earth from C114/3 for 85, as per wiring diagram. So far, all as planned.

Unfortunately, K1/30,87&86 are internally connected.
The wiring diagrams show terminal 86 as being the free one and 85 internally connected to earth.

The answer was that it is actually 86 that's earthed. (would have been a case of reversed relay?) Anyway, power from thermoswitch to 85 (sounds so wrong, though) and it should work.

But why on earth is my car wired like that???

I did find the black/violet going from the 5 pin "A/C " plug to the heater loom connector, the problem is that it stops inside the fusebox at the 5 pin plug and never joins K1... No good to me.

[DanThe]

Thats how mine is, fan switch is wired to pins 85 on both relays, 86 on K6 is grounded

[Brianmoooore]

Now that you've mentioned it, I think I've noticed this before and is normal. The wiring diagram has the relay pins transposed.

[suzie650]

... Been a bit stupid there... I did check 86 for ground yesterday already, and it wasn't... But I forgot that i had already cut out the earth wire from C114/3

[ian332isport]

The wiring diagram has the relay pins transposed.

Agreed.

[steve_k]

Phew need a new spade after digging this thread up lol

been reading through it as I'm looking at replacing the viscous fan with a electric pusher fan & after a bit of digging about I found a "fixed thermostat switch" with it's own sensor.

now what I want to know is does the sensor have to be mounted in between the radiator fins?? Or can it be mounted else where? Like in the top hose? Or before the thermostat?

I only ask as it switchs the fan on @82c.

any help & advise with this would be a massive help.

[Brianmoooore]

To work properly, the 'stat for an electric fan should be part way down the 'cold' side tank of the radiator. In fact, precisely where BMW place them.

[redcar]

I'm also a bit stuck on this.

I understand the wiring now, but am just a little confused.

How exactly do I accomplish this? "Power leaves the fuse box via fuse F19 and goes to the input side of the temp switch."

I opened up my fuse box by undoing the three self tapping screws, but couldn't see any obvious way of tapping into the power from F19. Likewise, would need to run power from high speed F18 and low speed F3.

Thank you and sorry for diverting the conversation a bit.

[HairyScreech]

Just knocking a wiring diagram up from ians instructions, will get it up once i have it fully down.

[steve_k]

To work properly, the 'stat for an electric fan should be part way down the 'cold' side tank of the radiator. In fact, precisely where BMW place them.

thanks for that Mr mooooooore, where. About's exactly is the cold side?? got a pic of the location so I know where to look??

[steve_k]

Just knocking a wiring diagram up from ians instructions, will get it up once i have it fully down.

excellent, thanks dude

like redcar I'm a bit (lot) stuck on the wiring side of this.
fingers crossed it's a simple diagram lol.

[Brianmoooore]

To work properly, the 'stat for an electric fan should be part way down the 'cold' side tank of the radiator. In fact, precisely where BMW place them.

thanks for that Mr mooooooore, where. About's exactly is the cold side?? got a pic of the location so I know where to look??

The boss for a 'stat is part way down the RH end tank of the radiator. All E34/36 radiators that I've seen have the boss, blanked off with a brass hex. plug if not used, and most replacement E30 radiators also have it, although original E30 radiators on cars without aircon, just have a raised ring in the plastic where the boss would be.

[HairyScreech]

Ok here is the official version and my rather ghetto but easy to understand 5 mins with a note pad version.

I need to do this myself for the 2.8 build and i have a spare fuse box so might get some photos as i go.

[steve_k]

Thanks for that Brian

just waiting for hairyscreech to post up that (simple?) wiring diagram now.

EDIT, he's just done it lol.

[Brianmoooore]

EDIT, he's just done it lol.

Everything in the top half of the hand drawn diagram is present in your fusebox already. The only wires you need to add are the three thin ones to the 'stat, and the heavier ones to the fan and resistor, with connectors on each end.

[steve_k]

@hairyscreech, thanks for that dude I'll get it printed off & whn I get the sensor I'll have a go at getting it wired up & working (firebrigade on speed dial lol).

[HairyScreech]

That is good to know, is everything in the fuse box already wired up then?
Just a case of insert relays and fuses and off you go?

If so i assume the wires then need to be added have to be put into pins in the fuse box, or are there some unused wire tails coming out of those pins?

[steve_k]

EDIT, he's just done it lol.

Everything in the top half of the hand drawn diagram is present in your fusebox already. The only wires you need to add are the three thin ones to the 'stat, and the heavier ones to the fan and resistor, with connectors on each end.

I take it the heavier ones are two wires only? As thats what the fan has.
sorry if that sounds a bit thick

[Brianmoooore]

No tails present in the fusebox. The added wires need to have the correct pins attached to the end of them to push up into the relay sockets.
The circuit diagram shows a two speed fan arrangement, using a high wattage resistor to drop the voltage to the motor for the low speed. The two heavy wires from the fusebox to the fan are the one that goes direct to the + terminal of the fan, and the one that goes to the + terminal via the resistor. This resistor generates a lot of heat, and has to be mounted on the frame of the fan, in the air flow.
If you just want to use a single speed fan, the wire that goes to the resistor and the resistor can be deleted, and the appropriate relay and fuse not fitted, although the lower temp. half of the thermo switch should be connected to the relay still in use, rather than the higher temp. half.

[HairyScreech]

yeah, the resistor and cable joint on my diagram are often in the fan, just added it incase its a single speed fan.

by the sound of it its a case of:
F3 thick wire to low speed on fan
F18 thick wire to high speed on fan
F19 thin wire to temp sensor
Temp sensor LOW thin wire to pin 86 K1
Temp sensor HIGH thin wire to pin 86 K6

The rest is done right?

And if going single speed then ignore F3 K1 and the resistor. All the rest is the same.

[DanThe]

That is good to know, is everything in the fuse box already wired up then?
Just a case of insert relays and fuses and off you go?

If so i assume the wires then need to be added have to be put into pins in the fuse box, or are there some unused wire tails coming out of those pins?

Wires you add need to have the connectors on to push into the fuse and relay spaces in the fusebox. I often make plug and play looms up for zoners doing engine conversions, either to work single speed or twin speed fans

[DanThe]

yeah, the resistor and cable joint on my diagram are often in the fan, just added it incase its a single speed fan.

by the sound of it its a case of:
F3 thick wire to low speed on fan
F18 thick wire to high speed on fan
F19 thin wire to temp sensor
Temp sensor LOW thin wire to pin 86 K1
Temp sensor HIGH thin wire to pin 86 K6

The rest is done right?

And if going single speed then ignore F3 K1 and the resistor. All the rest is the same.

You also need to add a ground to one of the relays, cant remember which but it is obvious with the fusebox open

[Brianmoooore]

Fan motor also needs a thick wire from its negative terminal to the earthing terminal on the inner wing, behind the LH headlamp.

[steve_k]

That is good to know, is everything in the fuse box already wired up then?
Just a case of insert relays and fuses and off you go?

If so i assume the wires then need to be added have to be put into pins in the fuse box, or are there some unused wire tails coming out of those pins?

Wires you add need to have the connectors on to push into the fuse and relay spaces in the fusebox. I often make plug and play looms up for zoners doing engine conversions, either to work single speed or twin speed fans

Dan how much do you charge to make up a plug & play loom for a single speed fan?

I might be in need of one soon let me know please dude?

[steve_k]

@danthe, forgot to ask what's included? Just the wiring? Or wiring & sensor?

[redcar]

Thanks for those diagrams, it's easy to understand the whole concept of the where to wire things etc. but i'm honestly lost with regards for how to run a wire from fuse 19 to the temp sensor. How do i physically run a wire from the fuse box to the temp. switch?

Cheers

[HairyScreech]

Will use my spare (possibly fire damaged) fuse box for a tutorial when i make my loom.

[Brianmoooore]

There's a rubber 'nipple' on the side of the fusebox nearest the wing, which you cut the end off to allow your new loom to exit the fusebox. Bind the new wires together with rayon (preferably) or PVC loom tape (not PVC insulating tape!) and run them in the same clips as the existing looms, over the inner LH wing towards the headlamp, then across behind the front panel to the fan and thermo switch, again using the existing loom clips.

[redcar]

There's a rubber 'nipple' on the side of the fusebox nearest the wing, which you cut the end off to allow your new loom to exit the fusebox. Bind the new wires together with rayon (preferably) or PVC loom tape (not PVC insulating tape!) and run them in the same clips as the existing looms, over the inner LH wing towards the headlamp, then across behind the front panel to the fan and thermo switch, again using the existing loom clips.

Ok thanks, I understand that.

Please can you advise where to get the pins to connect the new wires to the fuses and relays present in the fuse box?

Thank you

[Brianmoooore]

Pins are available from BMW, but may come in packet quantities.
Alternatively, there's probably a few on here who have bought packet quantities, and have surplus ones for sale.
The cheapskate source is to remove suitable pins from a scrap fusebox.

[redcar]

Pins are available from BMW, but may come in packet quantities.
Alternatively, there's probably a few on here who have bought packet quantities, and have surplus ones for sale.
The cheapskate source is to remove suitable pins from a scrap fusebox.

Thanks for that info. Do you know if the pins in an e36 firebox would be the ones I require.

Would I be correct in thinking that there are two different types of pin I need?

Thanks

[steve_k]

If you don't mind me asking what type of pin's/connectors do I/we need to be buying?

Thanks.

[HairyScreech]

http://bmwfans.info/parts/catalog/E30/T ... al_system/

one of these i guess

[Brianmoooore]

Would I be correct in thinking that there are two different types of pin I need?

Thanks

Different size wires use different sized pins, but you can get away with using only the larger type if you solder the smaller wires to them instead of relying on just the crimp.

No idea on E36 pins. The pins require a special tool to remove them and leave them reusable, unless you cut the plastic away that retains them.