Radiator fan

[HORCH]

right! I went back round the garage, unplugged the brown one and it stopped!

so thats my problem isnt it? if I get another one it should work?

it must have been my 110 yellow box making the buzzing noise

I havent got my rad fan in because a: my battery isnt charged much and b: it isnt fitted and I didnt want to just rest it in the bay incase it flew off and chewed some wires up or something

[S2central.net]

OK - the brown one is correct position for J155 then...

Grab its part number and also that 305 oddball - wanna know what that one is

[HORCH]

part number for the brown one is

447 965 571 A

it also has 14335 stamped one the side in red


part number for the black one with 305 on the top is

443 919 578 J

[Mikes2]

Has it been confirmed the relay is at fault ?

It could be also be the afterrun sensor in the water rail. Much cheaper to replace and even easier to diagnose.

disconnect the two sensor wires. if the fan stops, the sensor is duff. you can prove this by touching the two wires together and the fan should restart

[S2central.net]

That is very true. I was just focussed on helping get the radfan stopped 1st of all.

[HORCH]

do you mean these two wires on the left? if so I've just tried what you said and they still run?

so does this mean its definately the brown relay?

[S2central.net]

Thats the thermoswitch for afterrun alright... if fan runs when you have these wires unplugged (not touching anything else) then fault lies with that relay.

[S2central.net]

As for 305 relay (443 919 578 J) - that is a compressor clutch controller too.

So does your car have aircon and does it work ?

Does the position 305 sitting in actually have wires plugged into it ?

[S2central.net]

I was looking for evidence that your 305 might be worth trying in the empty position alongside it - and I found a trusty site ....

http://www.s2-audi.co.uk/tech_articles/electrical/relay_pos_4.htm

If your aircon has never worked - then you might be in for a nice cool surprise

[HORCH]

ahaaa! so I need a new brown relay!

the car had air con yes but I removed it, wether it worked or not, we'll never know?

but the place 305 is in now does have wires going to the back, and so has the space to the right of it?

so! once I get another brown relay I'll let you's know if it works as it should!

you know your stuff paul! thanks again for your help, rob

[S2central.net]

I dont have the schematic for 1992 manual aircon.. it might have had some different use of relays there too of course - mystery continues on that !

[veneto rs2]

Has it been confirmed the relay is at fault ?

It could be also be the afterrun sensor in the water rail. Much cheaper to replace and even easier to diagnose.

disconnect the two sensor wires. if the fan stops, the sensor is duff. you can prove this by touching the two wires together and the fan should restart

Yes it could be a faulty sensor but firstly you have to consider that even if the sensor it's faulty in close position the fan should run for a preset time of ten minutes then it must stop until a restart/switchoff sequence.

So that relay/ecu it's defenetely faulty.

Sensor as to be check as second issue IMHO.

Stefano