cooling fan not working

14th July 2013, 13:16

hi Ive got an X reg mk2 saxo and wondered if someone could give me a bit of advice/help basically my cooling fan won't cut in when it should I've checked everything fuses, the relay located to the top right of the fan, I've wired the fan up directly to see if the motor is broken and it's ok. any suggestions would be much appreciated

14th July 2013, 13:40

A the fan works itself.....so the fan is fine.fuse is good.

I'm guessing there is a temp switch which is fitted to the radiator.this sounds as if it is faulty,it may not be grounded properly or completely goosed.im sure you could pick one up cheap enough.

14th July 2013, 14:00

there's no temp switch In the radiator as that's what I first thought it was

14th July 2013, 14:42

How do you know it's not cutting in? Is the car overheating?

i.e is the gauge at max? or is the red light on?

If you got a gauge on the dash, the fan doesn't come on until it's at about 3/4. then it switches off again at 1/2way ish.

the temp switch for it is on the stat housing.

14th July 2013, 15:15

hi I know it's over heating as it used to cut in at a certain temperature and now doesn't and I'll try the temperature switch for it as I haven't tried that yet

14th July 2013, 16:09

when you unplug the temp switch, the fan should run (simlulates overheating)

14th July 2013, 16:14

Where ever the switch is it must be goosed........it can be tested or as above disconnect it and see what happens.

14th July 2013, 16:20

sweet thanyou for that I'll try disconnecting it and let you know how I get on

14th July 2013, 16:55

I thought on a mk2 the ecu controls when the fan cuts,ie no sensor on the radiator.

14th July 2013, 18:52

Quote:

Originally Posted by stevo67

I thought on a mk2 the ecu controls when the fan cuts,ie no sensor on the radiator.

Yes, temp sensor is on the stat housing! lol

14th July 2013, 19:44

Quote:

Originally Posted by MartinObviously

Yes, temp sensor is on the stat housing! lol

Well you learn something new everyday lol,as I was told differently.

15th July 2013, 02:41

Quote:

Originally Posted by stevo67

Well you learn something new everyday lol,as I was told differently.

You were right?

the ECU needs to know the temperature in order to cut the fan in or out, it uses a temp sensor on the stat housing!

god, some people on here drive me nuts

15th July 2013, 18:42

Quote:

Originally Posted by MartinObviously

when you unplug the temp switch, the fan should run (simlulates overheating)

I've just been put and tested the sensor on top of thermostat by disconecting it and then fan didn't cut in cut put the light up I dash to tell me that is was overheating

15th July 2013, 23:14

Quote:

Originally Posted by tomw1992

I've just been put and tested the sensor on top of thermostat by disconecting it and then fan didn't cut in cut put the light up I dash to tell me that is was overheating

Please try to attempt punctuation

You disconnected the sensor?
The dash light came on, the fans did not come on?

It's not the sensor then surely, if the light came on?

15th July 2013, 23:50

I do try to attempt punctuation but it's not my strong point

15th July 2013, 23:52

and no when I disconnected the sensor the fan didn't come on at all :/

15th July 2013, 23:56

sorry for pointing it out, just your sentence was hard to read

What engine do you have? ('im surprised nobody has asked you yet)

16th July 2013, 18:50

that's ok lol I'll even admit it was terrible lol and my engine is the 1.1

6th September 2018, 09:04

I know most of you probably don't have Saxos anymore, but I'll put this one here so people can see how I got it fixed.

I still drive a Saxo and it's my only car (I know, right?). Car is a 2002 Saxo VTR (MK2). Cooling was fine until one day when I went to tow a friends's Fiesta that was involved in an accident. While I was hooking the tow rope to both cars, I left my engine running... Got in car and the needle for the water temperature was higher than the middle line and light was on. So I immediately drove away... it cooled down fine at speeds of 30 MPH towing that Fiesta so it did not overheat.

I started investigating and the reason that I thought it stopped working was that I went to a pressure car wash last time I used the car and thought that because it's been sat for 3 weeks, probably there was a corroded connector.

Started investigating the issue, thermostat was good as my car would cool down while there was airflow through the rad... water temperature sensor in the stat housing was fine as it would show the temperature and the overheating light would go on. I needed to check the fan, so tried it with 2 wires connected to the battery and that was fine (inverted the poles first time I tried so it spun backwards... not an issue).

Went to halfords to get some 30A fuses and a fan relay as these were next on the list... didn't find a relay but changed the fuses that looked fine but just to be sure.

Ordered a Bosch relay from the net and with that, I could hear the clicking sound when removing the temp sensor plug.

So ECU was giving the signal to start the fan, fan did not work still...

By this time I was getting frustrated as I knew it must be some wire or connection... thing is, like many of us, I don't have much experience with these electrical problems. What I could determine myself was that I had permanent voltage (13.05V) at the radiator plug but no current. The way to test is to use a 21W indicator bulb and see if it comes on or not. Might be strange to hear that you have 13V at a terminal but the bulb doesn't come on.

At this point I though there was a bad earth so on the fan loom, I got the green/yellow wire off the body and noticed that the latter was very rusty. Cleaned it with a wire brush on the drill, contact spray and back on. Still no current so fan wasn't working.

At this point, I needed to strip everything to check the wires. Relay has 4 wires and I am not sure each what they do as finding a proper wiring diagram proved to be impossible.

The blue wire that comes to the relay apparently had to be a live feed.

Got the fan loom off of the car as I knew that it was possible. I had this to prove it:

So this is the Citroen Saxo microfiche that showed me that you can get the fan loom from the dealers (if stock is still available)... so I started getting the darn thing off of the car.

The only bit that didn't came off was the blue wire that goes to the engine compartment fuse box. So had it all out but that wire. I could now work my way through the loom. All the connectors on my car are amazingly clean. No rust whatsoever so ruled that out for now. Got the multi-meter out and checked the continuity of the live feed (blue wire) coming from the fuse box. Did that since I knew that I did not have enough current on the circuit.

There was no continuity in the blue wire. So pierced it half way and I had continuity between the pierced section and the fuse box, but not from the pierced section to the relay. Started stripping the loom for that half and found the problem:

Green stick failure! Very rare phenomena where you get a micro fissure in the outside insulation of a wire and moisture gets in. It then corrodes the wire to the point that it becomes so thin that it melts under the current and splits.

I had some blue same gauge wire available, cut off the section, soldered the new section on, heat shrinks, insulating tape, got all the plastic sleeves back, I did not cut the zip ties but reused them all, traced the loom as it was originally, you can't even see that it was tampered with and the job was well done. It should last for more that that car now.

I didn't even check the fan before getting all the bits back together, failure was obvious.

Simulated overheating by removing the temp sensor plug and as soon as the relay switched, the fan started working.

Hope this helps future frustrated people with their still working Saxos.

George M.

6th September 2018, 18:05

good fault finding.

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