From: DavidA on 18 Jul 2008 22:23 Hi My Mk4 Polo overheated today because the cooling fan is not working. I have checked the fuses. The Haynes manual suggests disconnecting the cooling fan thermostatic switch and bridging the relevant contacts in the wiring plug. Trouble is I can't find the switch. Haynes says it is mounted on the left-hand inner wing. Not sure which is left side in their convention. Is this on the coolant reservoir side? Any tips on how to locate the switch would be appreciated. Is it easy to replace the cooling fan motor? (It looks quite cramped in there). If so, is EuroParts the best bet for a competitively priced unit? Best regards David
From: Mrcheerful on 19 Jul 2008 03:48 DavidA wrote: > Hi > > My Mk4 Polo overheated today because the cooling fan is not working. > I > have checked the fuses. The Haynes manual suggests disconnecting the > cooling fan thermostatic switch and bridging the relevant contacts in > the wiring plug. Trouble is I can't find the switch. Haynes says it > is > mounted on the left-hand inner wing. Not sure which is left side in > their convention. Is this on the coolant reservoir side? Any tips on > how to locate the switch would be appreciated. > > > Is it easy to replace the cooling fan motor? (It looks quite cramped > in there). If so, is EuroParts the best bet for a competitively > priced > unit? > > > Best regards > > > David the fan switch is either in the edge of the radiator somewhere (reasonably certain that on yours is at the bottom of the rad), or on one of the hoses /housings at the engine. it will not be on the inner wing, the control module is on the inner wing (if you have one ). Some vehicles switch the fan by the ECU, but I don't think yours does.
From: DavidA on 19 Jul 2008 06:34 > the fan switch is either in the edge of the radiator somewhere (reasonably > certain that on yours is at the bottom of the rad), or on one of the hoses > /housings at the engine. it will not be on the inner wing, the control > module is on the inner wing (if you have one ). Some vehicles switch the > fan by the ECU, but I don't think yours does.- Hide quoted text - Thanks for your reply. Yes, I found the fan switch on the radiator. I pulled off the plug and linked the 12V pin to each of the other two in turn. One connection drew ~6A but the fan did not turn, the other drew 0A. So I guess the motor is faulty. I hoped to be able to replace it myself, but its so cramped around the fan mounting bracket bolts that I think its beyond my capabilities. Any further advice welcomed. David
From: Mrcheerful on 19 Jul 2008 06:55 DavidA wrote: >> the fan switch is either in the edge of the radiator somewhere >> (reasonably certain that on yours is at the bottom of the rad), or >> on one of the hoses /housings at the engine. it will not be on the >> inner wing, the control module is on the inner wing (if you have one >> ). Some vehicles switch the fan by the ECU, but I don't think yours >> does.- Hide quoted text - > > Thanks for your reply. Yes, I found the fan switch on the radiator. I > pulled off the plug and linked the 12V pin to each of the other two in > turn. One connection drew ~6A but the fan did not turn, the other drew > 0A. So I guess the motor is faulty. I hoped to be able to replace it > myself, but its so cramped around the fan mounting bracket bolts that > I think its beyond my capabilities. Any further advice welcomed. > > David while powering the fan have you given it a spin? sometimes if you coax it into life it will keep going, it may have got stiff to turn over the cooler months when it will rarely come on, if at all depending on your driving patterns. can't help with thinner arms and hands.
From: DavidA on 19 Jul 2008 15:48
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 |