Fan switch, where is it?

[s2driveruk]

Hi, driving in this morning on the m25 crawling in traffic and noticed that the first stage fan wouldnt start at just about 90 degs always reassuring in sub 15mph traffic. I confirmed it by trying to run the aircon, which you can hear/feel the compressor clutch engage/disengage. Then after a few minutes and the temp rising to mid 90's degs the 2nd stage sprung into life.....

Any idea why the first would fail but the 2nd stage run?

I need to pop out to GSF at lunch, any idea on the part number and its physical location in the engine bay, I can't remember anymore...



David

[Pete_RS2]

David,
Mine's had the same problem for a while now. Martyn swapped my rad fan switch (part no. 191 959 481 C)for me but it made no difference. It's located in the bottom of the rad.

We also swapped the fan relays around in the fusebox which made no difference either. Hopefully getting the resistor pack checked this week.

[S2central.net]

S2central.net tech section has some info on fan relay placement and other info...

[s2driveruk]

hmmm, sounds like a problem with many variables.....******. I have heard of problems with the resistor packs before, is there a simple way of testing/checking/replacing these as a matter of course or does it require some soldering?

Cheers guys,

David

[Pete_RS2]

You can do a continuity check on the 3 resistor terminals. On ABY/ADU there's a seperate resistor pack located underneath the n/s headlamp & bumper area. According to S2Central though it looks like the fan resistor network on 3Bs may be integral with the fan motor.

[S2 Ant]

I think my fan only runs on turbo speed, ive never seen it run at any other speed, apart from when the aircon is on and it runs at a lower speed, otherwise its full speed or nothing.

[Doug_RS2]

I think my fan only runs on turbo speed, ive never seen it run at any other speed, apart from when the aircon is on and it runs at a lower speed, otherwise its full speed or nothing.

Ant - check that resistor pack - I remember I thought the first speed never worked on your car and at one point I shorted the resistors out to test it - it was that long ago I can not remember if I put it back.

Does the afterun pump/fan mod not test the slow rad speed? Try shorting the temp sensor on the side of the block and see if the pump and the rad fan run for 10minutes.

[Pete_RS2]

There should be 3 fan speeds:

Low Speed works with a/c or afterrun pump.

Hi Speed-1 comes on at ~ 95 degC.

Hi Speed-2 comes on at ~ 102 degC.

[S2 Ant]

Thanks Doug, i'll take a look tomorrow as im off work.

IF the fan is running and i turn the ignition off it stops the fan also and ive never heard the after run pump either... think i'll be taking a look tomorrow

[s2driveruk]

if i turn the car off with the fan running, it also kills the fan, always has, though i think it isnt correct, having said that I can feel the afterrun pump working though, i just guessed that the coolant wasnt hot enough to invoke the fan

[porkkis]

FYI
3B cars do not have a resistor pack for the fan. Only a single resistor for the after run speed. 3B fans are internally 2 speed ones.
ABY cars have a 1 speed fan and a resistor pack.

[s2driveruk]

checked when i got home that the after run pump came on and it didnt feel like it, i.e. if i touched the top hose going back into the main radiator i couldnt feel it vibrating a little as normal?

So low speed fan and no after run pump - are these linked to a specific item thats failed...?