Radiator fan running constantly (S2 -93)

[S2central.net]

When you turn on aircon, it triggers the radiator fan to run as a way to help airflow over the condenser.

In very cold temperatures a thermal switch prevents the aircon from being activated due to risk of damage from pipes freezing on the low pressure / low temp side of the system.

What you describe is normal behaviour... it is good to run the aircon in the winter when you can as it keeps the system lubricated, but the control system is such that it fails safe (off) in very cold weather.

[valjo]

Hmm i dont think it is normal, or perhaps we dont undersant each other right
Problem is, that my radiator fun start runing when i turn keys (give contact) and ventilation is on. No mather if A/C is on or off. But if i turn ventilaton completly off, radiator fun stop working. It also stop working if i pull relay under dash out (relay for after run pump....)
Furhermore i dont have gas in my A/C so it can not star anyway

When you turn on aircon, it triggers the radiator fan to run as a way to help airflow over the condenser.

In very cold temperatures a thermal switch prevents the aircon from being activated due to risk of damage from pipes freezing on the low pressure / low temp side of the system.

What you describe is normal behaviour... it is good to run the aircon in the winter when you can as it keeps the system lubricated, but the control system is such that it fails safe (off) in very cold weather.

[S2central.net]

OHHH - in that case either your TCP relay is maybe faulty or something is messed up with wiring in that area...

Do you have manual a/c or climate control with digital head-unit ?

[valjo]

i have digital a/c

i am thinkinig the same, TCH and i hope wiring are ok ......
Could bad sensors on wather rail causes this too?
Could you give me any tips how to check signals on TCP connector under dash panel ?

Thanks

OHHH - in that case either your TCP relay is maybe faulty or something is messed up with wiring in that area...

Do you have manual a/c or climate control with digital head-unit ?

[valjo]

anyone

[veneto rs2]

Hi Valjo

The under dash "relay" it's actually an ECU for the afterrun system that controls also the working time (10mins max)

The MFS switch on the water rail could give you problem for the AC but AFAIK it's not in any way related to the fan system.

I had problems similar to yours (fan always on at 1st speed) and it was the under dash realy/ecu faulty.

It worth a check to the fan 1st speed relay on the fusebox also (top far left side if I remember well)


Stefano

[S2 Portugal]

Good afternoon all, I have a similar problem but before I get too carried away is anyone monitoring this post please?
Rgds, Julian

[Tractor Dave]

Always

[S2 Portugal]

S2 coupe, quattro, non A/C
The car is a 93 model but 92 registration with the ABY engine and six speed box, imported from Holland a few months ago and awaiting registration here in Portugal. Apart from a stage 2 turbo kit giving 270 bhp the car is original with just 64,500 kms on the clock. Haven't been able to use it much, still has Dutch plates so this fault came out of the blue.
It was sitting in the garage, locked with no key in the ignition and the radiator fan kicked in for just a few minutes then stopped. A few weeks later I heard the fan cut in (no keys, locked) but this time just kept running until it dragged the battery down when the fan stopped and the fuel pump kicked in! Had to disconnect the battery and charge it, left on trickle but as soon as it was reconnected the fan kicked in straight away.
Sounds very much like the car described above, does anyone know the part number of the relay please? Feel free to post any other ideas that you may have!
Regards, Julian

[Tractor Dave]

You need a new 324 relay, under the steering wheel on rhd car. Part number 447965571a. They pop up second hand now and again but might have the same fault. There is a zender diode inside that fails and they can be repaired. The diode is pence but you need to be good at soldering to fit it.

[Tractor Dave]

https://www.s2forum.com/forum/techni...-new-324/page3

[S2 Portugal]

Good afternoon Dave, thank you for the help so far; I think we are narrowing it down!

Here are a couple of photos, I think it's relay no 214 at the front. All in German on the fuse box cover but translates to "cooling air fan stage 1"

[Tractor Dave]

No. It's not that one. It's the one in the kick panel under the dash. Relay 324 as I stated above

[psiconauta911]

I did have the same problem, Stopped the car and locked and the fan stayed on, I removed the 214 and it stopped and reinstalled the 214 and it never happned again.

[S2 Portugal]

Good afternoon Dave,
Thank you so much, I have found the relay and pulling it out cures the overun, will now source a new one!
As you said it was under the steering column, a point to note on a LHD car is that it's in exactly the same position but on the other side of the car.