elec fan loom wiring diagram

[kevo]

hi all, thought i'd post up a picture (done with pencil in the rain and wind so excuse the poor quality), anyway it shows how to wire up a two speed e36 air con fan using the e36 ti 80/88 deg fan switch to the fusebox original fuse and relay locations.
hope it helps, any things unclear give me a shout.
cheers
Kev


bottom left is the fan with two speeds and an earth point

speed 1 connects through fuse 3 in the fusebox to relay k1 terminal 87

speed 2 connects through fuse 18 in the fusebox to relay k6 terminal 87

the temp switch has three pins '0', t1 and t2

'0' goes to fuse 19 (there is a small multiplug with about 6 wires going to it in the fusebox somewhere, check for continuity to the small green and black wire and cut it and join to terminal '0')

t1 goes to terminal 85 on relay k1

t2 goes to terminal 85 on relay k6

terminal 30 on both relays is already wired to 12v dc so you don't need to do anything

terminal 86 on k6 needs to go to earth

terminal 86 on k1 is already earthed so no need to do anything

[deanocool]

cheers mate thats well handy. will use this over this weekend to get mine in! sticky?

[gudgeon]

With this temp switch, does t1 stay closed when t2 closes. Or to put it another way, at high temperatures both fan inputs (speed1 and speed2) are live?

I've looked at the BMW wiring diagrams in my Bentleys manual and it's done another way with speed1 disconnected when speed2 is live. Funnily enough there's something suspect about that diagram too depending on how the relay works.

EDIT: Here it is:

The important stuff is in the bottom left.
The problem I see with it (and I'm probably wrong) Is that when the high speed relay is open BLU is live, whereas when it's closed normal speed relay comes into play. It seems to me that 2&5 on the high speed relay should be wired the other way around?

[deanocool]

from what ive read on here, when the higher temp pin switches on the lower temp pin goes dead. there is only one fan feed pin live at any one time (if thats true) hence 2 seperate relays for fast and slow.

[gudgeon]

Fair enough, probably depends on the switch.
Doesn't look like that's the intention from the BMW wiring diagram.
Some expert will be along shortly to put me right.

Below is a massively simplified version of the above, and it should be clear why this is probably wrong.


But I reckon the definitions are correct and the diagram is wrong, so it should look like this:


Sorry to hijack the thread, I'll go away now.

[Brianmoooore]

The diagrams in the last post are not as any E30 I've seen! The feed to the temp switch common should be a switched live, not a earth, and this diagram shows a proper two speed motor, with three brushes, such as is used for the wiper motor. The fan motor is a single speed motor, which is run through a resistor to make it run slower, or is fed after the resistor to make it run at full speed.
Both fan inputs will be live whenever the motor is running, as it will back feed through the resistor.

[DanThe]

Those last two diagrams are E36, the E36 and E34 uses switched earth to fire the relays

[gudgeon]

Yes, those are from the E36 Bentleys manual (simplified).

Sounds like (courtesy of Brian) it depends what fan type you are using. I'd better check mine.

[Brianmoooore]

E36 and E34 fans are both single speed motors, the same as the genuine E30 version.
Current stuff uses PWM for speed control, AFAIK.

[gudgeon]

Well the one I have calls itself 64548364093, which seems to google-out only polish pages.
Seems the same as a 64508364093 though.

It's dual speed, but certainly this could be acheived using resistors internally.

[Brianmoooore]

I doubt if any resistor would be internal, as it dissipates a considerable amount of heat.

[gudgeon]

Fair enough. I'll put a meter across the 2 inputs.

Was the original question ever answered? Would you expect t1 to stay closed on the switch when t2 is closed? (at high temp?)