I notice the auxiliary fan at the front of the radiator come on and off when the A/C is on, but I have still never seen it come on when the car is running without the A/C.
As I understand it there, are two relays, for 2 speed operation, how can I test the operation of my fan?
Where is the temp' sensor?
Just me looking for problems again
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95 E34 3.8 M5 6spd
87 Capri280 Turbo Technics, +290bhp@17psi [Not Currently For Sale]
There should be a temperature switch on the top right (or could be left) corner of the radiator with 3 wires coming out of it, if you short the brown and either of the other 2 wires the fan will run at low speed or high speed. The relays for the aux fan are in the auxiliary relay box in the engine compartment. In normal operation the fan will only run in high speed mode when the car starts to overheat.
I'm working through a laundry list of minor issues on my car. After reading this post, I decided to dig nto my aux fan problem.
The auxiliary fan runs continuously on my M5, I suspect it is high speed, but it could be low.
I disconnected the coolant temp switch with no change. I can stop it by pulling either fuse 25 or fuse 29.
I've only owned the car for a week and haven't purchased a proper manual yet (but I will) I've been digging through several BMW forums, searching on "aux fan". Most threads deal with a fan that will not operate - mine won't shut off LOL
I'm working through a laundry list of minor issues on my car. After reading this post, I decided to dig nto my aux fan problem.
The auxiliary fan runs continuously on my M5, I suspect it is high speed, but it could be low.
I disconnected the coolant temp switch with no change. I can stop it by pulling either fuse 25 or fuse 29.
I've only owned the car for a week and haven't purchased a proper manual yet (but I will) I've been digging through several BMW forums, searching on "aux fan". Most threads deal with a fan that will not operate - mine won't shut off LOL
There is a small relay box under the bonnet LHS, just in front of the fuse box, I think it is called the Auxiliary Power box or somehting like that.
Inside you will find 3 relays, possibly more, but on my car there are 3, 1 large which controlls the headlight washers, and 2 others which control both the slow and high speed for the auxiliary fan.
It is possible that one of them is jammed on...
I have not looked further into my auxiliary fan, in that I know it comes on with my A/C but have yet to see it coming in when stuck in trafic etc.
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95 E34 3.8 M5 6spd
87 Capri280 Turbo Technics, +290bhp@17psi [Not Currently For Sale]
There is a small relay box under the bonnet LHS, just in front of the fuse box, I think it is called the Auxiliary Power box or somehting like that.
Inside you will find 3 relays, possibly more, but on my car there are 3, 1 large which controlls the headlight washers, and 2 others which control both the slow and high speed for the auxiliary fan.
It is possible that one of them is jammed on...
I have not looked further into my auxiliary fan, in that I know it comes on with my A/C but have yet to see it coming in when stuck in trafic etc.
Not wishing to worry you or anything but if your aux fan is jammed on you probably want to get it sorted pretty sharpish. I've just checked a recent invoice from when my aux fan seized + a/c stopped working. Cost of the aux fan alone is £208.34 + VAT + fitting!
There are 2 things which will make the fan come on 1) The temperature switch on the radiator (with 3 wires coming out of it) 2) The pressure switch in the aircondtioning drier/receiver.
As you have already tried disconnecting the temperature switch I would suspect that the pressure switch is faulty ?
Miles
Quote:
Originally Posted by prairieman
It would appear that I gonna need a wiring diagram.
I pulled the high speed relay and replaced it - no change. For whatever reason, there is power to the relay whenever the key is turned on.
There are 2 things which will make the fan come on 1) The temperature switch on the radiator (with 3 wires coming out of it) 2) The pressure switch in the aircondtioning drier/receiver.
As you have already tried disconnecting the temperature switch I would suspect that the pressure switch is faulty ?
Miles
A little OT, but where then would the temperature sender unit be, for the temperature gauge?
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95 E34 3.8 M5 6spd
87 Capri280 Turbo Technics, +290bhp@17psi [Not Currently For Sale]
Linear Mode
