Radiator fan stopped working

[robobobo]

Hi everyone
This is a bit on the fly as I'm camping in the van and trying to fix it whilst holidaying
In busy traffic on yes probably the hottest day of the year, my fan was cutting in fairly regularly. I suspect now after checking the test procedures on the wiki that it only has worked at full speed for some time. It would blow for maybe 3 or 4 seconds then turn off. Maintaining steady temp halfway or just above! The needle gets to nearly past the LED when it kicks in.
Then the last time I heard it was just for a second then it did not come on again. Temp rose very quickly although I stopped in good time, was coming out of Kings cross on the A40 so was pretty hard to pullover till the flyover. I left the van to cool suspecting that it would be turn around time but when I restarted and got on the open road the temp was fine with no fan. In traffic I would switch off and made it to my destination.

I have tried the test on the temp switch https://club8090.co.uk/wiki/Co ... diator_fan" onclick="window.open(this.href);return false;
If I follow the instruction to go from the middle to either side one by one, nothing happens. However if I ignore the middle and go from outside to outside then the fan comes on ? I just tried it quickly a couple of times and this works great. I'm not positive but I think when I do this it's coming on at the lower speed.

Any ideas of how to go about it from here. I'm guessing that the fan could be faulty in some way although it's obviously working ? Fuse is fine at no1 and I have just cleaned and reattached all the earths and crowns behind the fuse box. Does this sound familiar to anyone? It's bloody hot as we all know and I'm a bit worried about continuing down to Cornwall as intended without getting this sorted. Although It's my holidays so I will

Would it be worth me taking out the thermostat for a wee while till I get sorted? Not ideal I know. Any advice appreciated. It's 2.1 DJ with the injection system complete.

Thanks
Robin

[robobobo]

Ps I had no paper clip handy so used some reasonable duty copper wire from a car stereo loom. Could that cause fan not to kick in due to the heavy ampage and it's perhaps a busted thermo switch???

[MidLifeCrisis]

Can any confirm if the Wiki test is correct?
I have the radiator out at the moment and had a look at the temp sensor;
If you peer inside at the three connectors on the sensor - they are labeled '+', '1', '2' in that order.
I took this to mean that the '+' is positive, the '1' is low speed/temp, and '2' is high speed/temp?
Is this not correct.

In which case the Wiki should be telling you to jumper an outside terminal to the centre for low speed, and the opposite side for high speed (not the centre one to each outisde one)?
Unfortunately I don't have a proper connector for that sensor - my wires just end in spade connectors so I have to attach them individually so I'd also be interested to hear others thoughts?

Any ideas/thoughts?

[AdrianC]

Forget what Wiki says about which pin is which.

Got a multimeter? Good. EVERYBODY should have one.
Find out which of the three is +12v.
That's the supply. Now jump (You can't use too big a bit of wire, only too small) that to one of the pins, then the other. You should get a very loud whoosh from one, and a quieter one from t'other.
If you do, then the fan switch is dead. No more, no less.

Have a read from here onwards...
https://club8090.co.uk/forum/viewtopic.p ... 5#p7901645" onclick="window.open(this.href);return false;

If none of the three pins is +12v, then there's a problem in the supply.
If neither of the other pins gives you a whoosh, then there's a problem with the fan motor.
If only one of the speeds gives a whoosh, then you've got a problem in the other one.

[MidLifeCrisis]

Forget what Wiki says about which pin is which.

What!!!! What are you saying ......
All my faith in the goodness of Wiki is dashed!!

And cheers for the other info .... will poke with multimeter and see what's what!!

[bigherb]

No the wiki is wrong.
As midlife says the switch is marked + or 3 which is the power supply 1 and 2 are the outputs. So as you have done you bridge the outside terminal + to one of the other two to get the fan to work low or high speed.
As you have the fan working on one of them then the fan switch is faulty for the low speed, and possibly now the relay for fast speed has now burnt out. You really need to check again which speed is running when you bridge it out.

[robobobo]

Thanks for the info, very helpful. Sorry for the delay but the phone is intermittent on the campsite.

So yep looks like Wiki is wrong, unfortunately my multimeter in the van has lost its leads. What I have found though is that yes the fan is only working on high speed (red blue 3) and not low (red black 2). I guess that means either my temp switch is now failed or my cleaning the earths has solved the problem of the high speed. When I get up to temp it will either work again or I need to replace the switch.

Also means as I thought that my low speed has not worked whilst I have owned the van.
:- Both speeds will be the same earth so this is not the problem ?
:- there is only 1 terminal live on the fan with 2 wires going to it so the fan is not the problem but the supply for the low speed?

So is there a relay for the low speed or is it the same as the high speed? Where would I find it and where should I check the wires for power. If I get the high speed back on then it's not so urgent but if it's an easy fix to check a relay or some wiring connections then I could have a go.
I've only just last week got it going again after replacing half the ignition components. Getting there though. Sounding sweet apart from not having the reassuring whoosh of the fan.
Cheers guys

[bigherb]

There you go.
Only the fast speed has a relay.
Two types of high speed fan the 200/300w has the relay in the fuse box, the 450/500w has the relay and additional fuse mounted on the A pillar by the earth crowns.

[robobobo]

Thank's Herb, much appreciated
Radiator fan is kicking in at high speed again. Ill use your diagram to troubleshoot the low.
cheers