No after-run on my cooling fan

[HPmuirt]

Hey folks....time to test that grey matter.....

My cooling fan does not run when I turn the ignition off, but I have checked all fuses and relays and still cannot get to the bottom of this one. I assume that as with my 2.8 Coupe, the ABY S2 fan should continue running, along with the afterrun pump, when the ignition is switched off?

The fan runs fine, kicking in at 90 when idling and still runs when the engine is then turned off but the ignition remains on. However, as soon as I turn the ignition off, the fans stops

Can anyone shed any light on this...please

I have no known blown fuses and have changed all 3 small grey relays in the engine bay fuse/relay box which are numbered 214 (I thought they were the fan controllers).

Cheers n

Si

[S2 Ant]

Mine has always done this as well and I thought it odd that the fan just stops with the ignition off.

I have the added problem that i dont think my after run pump has ever worked.

[Jas11n]

Have you checked MikeS2's post about fuse 20 ??

Jas

[HPmuirt]

Have you checked MikeS2's post about fuse 20 ??

Jas

Hey matey,

Yup, just rechecked it. 2nd fuse from right (30Amp) present and correct. It states in that thread that shorting the sensor pins short start both the pump and fan at speed 1....any idea on the exact location of this sensor? If I short it, it will tell me if my pump works and if the electrics for the afterrun fan are all OK.

Cheers n

Si

[Jas11n]

Hey matey,

Yup, just rechecked it. 2nd fuse from right (30Amp) present and correct. It states in that thread that shorting the sensor pins short start both the pump and fan at speed 1....any idea on the exact location of this sensor? If I short it, it will tell me if my pump works and if the electrics for the afterrun fan are all OK.

Cheers n

Si

Seems like it's the two pin sensor located on the water manifold under the inlet manifold. Time to supple up and contort yourself to have a look

Jas

[Billman]

That is the Sensor! It goes on when the water temperature is 110 Celcious! That is too much! I have buy one that goes on at 85 Celcious but still not got any time and knowledge how to fit it the easiest way (means without moving the Rad)! With this it will go on almost after every drive witch would be nice for the Turbo (and hopely for the Battery too)!

Maybe i call it the Billman Mod myself???

[Mikes2]

You don't need to disturb the rad to undo this sensor. Small hands are helpful but you can reach in with a 22mm spanner upside down. It's easier if you remove the wiring from the larger 4 pin sensor next to it.

Touch the 2 wires together. If the fan doesn't start, there's a fault somwhere else - probably the afterrun control relay which looks like this



Position 14 under the dash

[HPmuirt]

You don't need to disturb the rad to undo this sensor. Small hands are helpful but you can reach in with a 22mm spanner upside down. It's easier if you remove the wiring from the larger 4 pin sensor next to it.

Touch the 2 wires together. If the fan doesn't start, there's a fault somwhere else - probably the afterrun control relay which looks like this



Position 14 under the dash

Hi Mike,

Fabulous, thanks for the info. I have just collected a full set of spare relays from a scrapped car, but that one is now in the set ....murphy's law eh?

I have not managed to locate this sensor yet as it is cold and dark (had a quick look with the torch) I don't suppose you know of a piccie of this area do you?

Also, I assume that I don't need the spanner to get at the wires to test the circuit?

Cheers n

Si

[Billman]

Upsidedown you mean i should try to reach it from under the car??

There a procedure from audi to test this system! They say you leave the car idling till the Water temp goes over 100 Degrees (if nessesary put something in front of the Rad to block the air) and then turn off the engine and ignition! You should wait till 5 minutes for it to start! If it don't starts then you have a problem!

Another check for the Electric pump is that every time you turn the ignition on the pump runs for ca. 5 seconds! You can feel it with your hand vibrating!

I am definatly going to install this other sensor to mine so it runs after every drive (something like a turbo timer) It will start whenever the water temp is above 85 and i switch off the engine till it goes under 80 grad celsious!

[Jas11n]

I don't suppose you know of a piccie of this area do you?


Cheers n

Si

Here it is. A = two pin one you are looking for. B = MFTS

Pic is from a thread by Angus (AAH!) but I couldn't get it to attach, so copied and hosted it.


Jas

[Mikes2]

http://www.s2-audi.co.uk/tech_articles/afterrun.htm

is one I prepared earlier.

No spanners required - just skinned knuckles. Just make sure the 2 wires don't touch anything else - especially the inlet manifold - when you've disconnected them (experience speaking here).

#1 fan speed is very quiet and the aux water pump you will not hear running.

The sensor is upside down so you turn it clockwise to undo it if you want to remove it.

[HPmuirt]

Mike and Jas, I salute you both....now go to bed

Many thanks

Cheers n

Si

[S2central.net]

Some cooling system info here - and follow the diagnostics link for TCP test info.

http://s2central.net/cooling01.html

Paul

[dan_b]

My main fan goes off when you switch off the ignition too, but I have heard the after-run fan coming in this summer - this seems to happen after about 5mins from switching the car off .

[Billman]

Is there any how to remove it??? I have the 85 Grade one but i cant change it! I can use any instument there!