Mk4 Polo - Cooling fan not working
in [Car Maintenance]
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From: Chris Bartram on 19 Jul 2008 16:06 DavidA wrote: > Thanks for your replies. I'm mystified on two counts: > > Firstly, my comment about testing the motor above was wrong - I was > using my multimeter incorrectly. I now find that linking the 12V pin > on the fan switch connector to one of the other pins does indeed cause > the motor to spin. However, connecting 12V to the other pin causes no > spinning. Assuming this really is a two speed fan (which Haynes > suggests it is) that can only mean a wire in the harness is broken or > the resistor in the motor has blown. However, when I reconnect the > plug and run the engine until the temperature is 90C, the fan does not > come on at all (which is why I find it overheats on a run). So this > implies that the fan switch is faulty. But surely the switch and the > motor resistor are unlikely to both be faulty? It seems to me that the > motor is really only single speed and the fan switch is faulty. Any > thoughts please? > > Secondly, I think I would need minute hands to get the motor fan > cowling off. Is it possible that I should remove the battery and > battery shelf to do this? > > Advice appreciated! Trying to avoid a high dealer bill. > > David Golf IV fan resistors are famed for blowing so that speed 1 fails. This page: http://www.nime.co.uk/mk4fans.html suggests the resistor is in the motor, and lists a module that will do the same job. 2 speed fans are usually only fitted with aircon IIRC. Does your Polo have it?
From: DavidA on 19 Jul 2008 17:30 > 2 speed fans are usually only fitted with aircon IIRC. Does your Polo > have it? No, my Polo doesn't have aircon. I guess that explains that then. So I suspect the thermo switch is the problem. Any tips on replacing it? Thanks. David
From: Duncan Wood on 20 Jul 2008 07:15
On Sat, 19 Jul 2008 20:48:43 +0100, DavidA <dandbnews(a)talktalk.net> wrote: > Thanks for your replies. I'm mystified on two counts: > > Firstly, my comment about testing the motor above was wrong - I was > using my multimeter incorrectly. I now find that linking the 12V pin > on the fan switch connector to one of the other pins does indeed cause > the motor to spin. However, connecting 12V to the other pin causes no > spinning. Assuming this really is a two speed fan (which Haynes > suggests it is) that can only mean a wire in the harness is broken or > the resistor in the motor has blown. However, when I reconnect the > plug and run the engine until the temperature is 90C, the fan does not > come on at all (which is why I find it overheats on a run). So this > implies that the fan switch is faulty. But surely the switch and the > motor resistor are unlikely to both be faulty? It seems to me that the > motor is really only single speed and the fan switch is faulty. Any > thoughts please? > If the switch has been faulty for a bit then the resistor tends to die. Polos have had two speed motors since the 70's, change the switch & see if it's happy. > Secondly, I think I would need minute hands to get the motor fan > cowling off. Is it possible that I should remove the battery and > battery shelf to do this? > My memory could be vague here, but you unbolt the front valance, disconnect the hoses & lift the radiator, cowl & fan out as one. > Advice appreciated! Trying to avoid a high dealer bill. > > David |