radiator fan switch

3rd April 2013, 13:39

I finally got round to testing the sensors on my 1.5d to find out if any of them were the reason why my cooling fan isn't working. I put a piece of copper wire onto the plug that connects to the radiator fan switch and the fan started running! .. First time in ages.

Does this mean the plug that connects to the radiator fan switch is faulty?
If so, where can i get a new one from?

Thanks for any advice and help in advance!

3rd April 2013, 13:43

a motorfactors should do them

3rd April 2013, 13:43

Quote:

Originally Posted by Pink1991

I finally got round to testing the sensors on my 1.5d to find out if any of them were the reason why my cooling fan isn't working. I put a piece of copper wire onto the plug that connects to the radiator fan switch and the fan started running! .. First time in ages.

Does this mean the plug that connects to the radiator fan switch is faulty?
If so, where can i get a new one from?

Thanks for any advice and help in advance!

No means the Thermo switch in the rad is fucked. Can get em on ebay for about a fiver.

3rd April 2013, 13:47

Quote:

Originally Posted by Bedford126

No means the Thermo switch in the rad is fucked. Can get em on ebay for about a fiver.

I only replaced it about 2 months ago as i had suspicions of the switch being the problem, but still no luck

3rd April 2013, 13:49

Quote:

Originally Posted by Pink1991

I only replaced it about 2 months ago as i had suspicions of the switch being the problem, but still no luck

Did you test it before you fitted it?

Take it out then boil the kettle put the plug in the switch and then put the brass bit into the water. If the fan kicks in then its not the sensor.

3rd April 2013, 13:55

Quote:

Originally Posted by Bedford126

Did you test it before you fitted it?

Take it out then boil the kettle put the plug in the switch and then put the brass bit into the water. If the fan kicks in then its not the sensor.

Il have to give that a try mate. Ill post back up when ive tested it. cheers!

3rd April 2013, 14:45

Or just check the resistance when the car is cold with a multimeter as opposed to when its hot. If its not a lot when warm then your switch is good. But its 99% chance going to be that switch, providing the car is getting hot enough to activate it of course. Thats where the adjustable resistivity ones come in

3rd April 2013, 15:18

Quote:

Originally Posted by Gandi699

Or just check the resistance when the car is cold with a multimeter as opposed to when its hot. If its not a lot when warm then your switch is good. But its 99% chance going to be that switch, providing the car is getting hot enough to activate it of course. Thats where the adjustable resistivity ones come in

The cars definitly getting hot enough and the switch is new. cant see where the problem is. The only thing i can think of is the brass block the screws into the radiator has two prongs sticking out for the plug to connect to. but the plug that connects has three sockets. as if theres suppose to be three prongs coming from the brass block.

3rd April 2013, 15:25

are there 3 wires leading from the plug into the loom?

3rd April 2013, 15:32

Quote:

Originally Posted by Gandi699

are there 3 wires leading from the plug into the loom?

yes there is mate. two blue and one yellow ( dont know if that makes a difference or not )

3rd April 2013, 17:11

anyone have any idea what the problem might be?

6th April 2013, 21:43

thought id continue posting on here instead of making another thread.

Okay so i tested the fan switch in some boiling water and the fan kicked in so i know the fan switch is actually working. But when its connected to the rad the fan never kicks in, even after a 120 mile drive i done the other day. So im assuming the radiator is knackered? It has defiantly seen better days, a lot of vains have fallen off from the front of rad and there's some white frosting around the top rad hose so somethings up. I can only assume now it needs a new rad?

6th April 2013, 21:45

Does the top hose get hot after a long drive? If not then its your thermostat.

6th April 2013, 21:50

Quote:

Originally Posted by Bedford126

Does the top hose get hot after a long drive? If not then its your thermostat.

it never use to, so i changed the thermostat and it does now so i know its not that

6th April 2013, 21:53

whats it do if you leave the car idling for a good 30mins or so? in most driving conditions the fan wont come on due to air flow through the rad (even though yours sounds like its shot)

6th April 2013, 21:55

Quote:

Originally Posted by Gandi699

whats it do if you leave the car idling for a good 30mins or so? in most driving conditions the fan wont come on due to air flow through the rad (even though yours sounds like its shot)

If i sit there and leave it to idle. As the car warms up it idles lower and lower, untill it idles at 500 rpm. im now having to put the heaters on full to cool it down slightly then it will sit at around 600 or just below.

6th April 2013, 21:56

also runs like shit, feels weak, shakey and vibrates quite a bit. So annoying that the diesels dont have a temp gauge!

6th April 2013, 21:57

so even if the gauge is getting 3/4s its not coming on? I'd be inclined to get one of those cheap ebay adjustable controllers and wire that in as a test

6th April 2013, 22:01

Quote:

Originally Posted by Gandi699

so even if the gauge is getting 3/4s its not coming on? I'd be inclined to get one of those cheap ebay adjustable controllers and wire that in as a test

The diesels dont have a gauge lol

i cant tell how hot its getting its so frustrating. and controllers?

6th April 2013, 22:10

oh I forgot that its got a base spec dash hmm so you dont know if its getting hot enough then - I'd suggest its not getting warm enough to put the fan on. Dont the base specs have a light to indicate its getting too hot?
Theres some adjustable controllers on ebay, you wire it in to power the fan and its adjustable by a rheostat as it uses a probe in the top hose too and you can set it when you want it to come on

6th April 2013, 22:14

Quote:

Originally Posted by Gandi699

oh I forgot that its got a base spec dash hmm so you dont know if its getting hot enough then - I'd suggest its not getting warm enough to put the fan on. Dont the base specs have a light to indicate its getting too hot?
Theres some adjustable controllers on ebay, you wire it in to power the fan and its adjustable by a rheostat as it uses a probe in the top hose too and you can set it when you want it to come on

Yeah it does have a light but only comes on when i switch the ignition on. never seems to come on as if the car is overheating or anything. But im pretty sure its getting too hot. I have a strong feeling its the rad not doing its job properly. And it seems like a good idea but seems like a bit too much of time and effort to get the fan working mate

6th April 2013, 22:16

Replace the rad and go from there then I think. the adjustable controllers arent too bad its not a lot of effort really for £7 and an hours work, but frankly the switch should be doing its job. Even if the rad was knackered the fan would still come on, probably earlier as it'll get hotter quick due to reduced efficiency.

6th April 2013, 22:19

Quote:

Originally Posted by Gandi699

Replace the rad and go from there then I think. the adjustable controllers arent too bad its not a lot of effort really for £7 and an hours work, but frankly the switch should be doing its job. Even if the rad was knackered the fan would still come on, probably earlier as it'll get hotter quick due to reduced efficiency.

ah i see i didn't think of that. I just cant understand why its not coming on. all sensors and switches have been tested and all work as they should. The rad is the only thing i can think of now

Anyway yeah i think ill get a new rad anyway as the current one looks shagged. If that dont do the trick, ill try the controller

Cheers for your advice and help mate, greatly appreciated!

6th April 2013, 22:36

Have you got the right sensor, and the right stat

The 1.5 doesnt run very hot at all

6th April 2013, 22:38

Have you thought maybe the water temp never gets to the temp where the fan needs to kick in?

6th April 2013, 22:41

As above... My diesel never got not enough to kick fan in

And that's waiting 20+ minutes for the other half

If you put the heaters on when sitting it can close the stat lol! And my rad was clean as fuck

6th April 2013, 22:42

Quote:

Originally Posted by Bedford126

Have you thought maybe the water temp never gets to the temp where the fan needs to kick in?

how would i know if its the water temp?

6th April 2013, 22:44

Quote:

Originally Posted by blackie_2k5

As above... My diesel never got not enough to kick fan in

And that's waiting 20+ minutes for the other half

If you put the heaters on when sitting it can close the stat lol! And my rad was clean as fuck

ah i see, my mum was saying how her old diesels fan never kicked in either buti thought it was just her being silly ... lol
Believe me, my rad is far from being anywhere near good

6th April 2013, 22:58

Quote:

Originally Posted by Pink1991

ah i see, my mum was saying how her old diesels fan never kicked in either buti thought it was just her being silly ... lol
Believe me, my rad is far from being anywhere near good

your rad would have nothing to do with the fan kicking in.

6th April 2013, 23:04

Quote:

Originally Posted by Bedford126

your rad would have nothing to do with the fan kicking in.

but the fan switch plugs into the rad? surly it would if the rad was blocked or ruined wouldnt it?

6th April 2013, 23:07

Quote:

Originally Posted by Pink1991

but the fan switch plugs into the rad? surly it would if the rad was blocked or ruined wouldnt it?

The switch is directly under the inlet in the rad. It would take one hell of a huge blockage to block it to stop hot water hitting the switch.

6th April 2013, 23:11

Quote:

Originally Posted by Bedford126

The switch is directly under the inlet in the rad. It would take one hell of a huge blockage to block it to stop hot water hitting the switch.

true What else could it be though? so far ive checked sensors and fan switch all fine, replaced thermostat, replaced fan switch and drained and replaced with all new coolant as i duno what was in there before and its still having problems with idling low and running shit. ( As it would when a car gets close to overheating )

7th April 2013, 16:10

Okay the radiator isnt blocked and im pretty sure the coolants getting so i think im going to just wire in a toggle switch into the dash and flick the fan on and off manually.

Has anyone else done this? if so is it an easy enough job to do myself?

16th April 2013, 20:35

Sorry for using this old thread, again i thought no point in making a new one.

Anyway, checked under bonnet today when the car was running and was hot and found smoke coming from the rad! Pics are of where i think it was coming from... Could this be the reason im having all these problems?

16th April 2013, 21:57

Looks like you have a hole in your rad

16th April 2013, 22:16

Quote:

Originally Posted by blackie_2k5

Looks like you have a hole in your rad

With a 25% discount i can get a brand new rad from europarts for £60, not bad tbh. Think im just going to replace it. Is it hard to replace the radiator? how long does it take?

17th April 2013, 09:29

half an hour max, that includes bleeding the system too.
That ones got the the blue tinge of corrosion to the fins, fit for the bin tbh

17th April 2013, 09:57

sounds like you have the wrong fan switch too.