ocrp Posted September 14, 2006 Report Share Posted September 14, 2006 I've posted about this issue a couple a months ago, but it was a bit inconclusive, as it was during the hot summer months. I have been leaving the Climatronic on Auto (aircon on)quite a lot these days, as it helps prevent steaming-up windows, especially in this humid weather that we've had recently. However, this seems to activate the main engine cooling fan, even when the engine is cold and the outside temperature is 18 degrees. It comes on ususally for short periods, maybe 2-3 minutes. This only happens when using the aircon, when I switch to Econ mode, the fan turns off. This wasn't abnormal in the hot summer, but surely it should not be happening now, with a cold engine. Is this a coolant temp sensor problem? The temp guage functions as normal, and I had the coolant temp sender changed last year. As usual, any ideas appreciated. Link to comment Share on other sites More sharing options...
ocrp Posted September 20, 2006 Author Report Share Posted September 20, 2006 I have seen posted on another forum that this can be a problem with the high pressure switch on the A/C, which is temperature sensitive. The problem has definitely gone worse since the dealers regassed me in the summer. Has anyone had this issue? Link to comment Share on other sites More sharing options...
ocrp Posted October 3, 2006 Author Report Share Posted October 3, 2006 Ok, I've located the fault, aircon cooling fan has failed. That would explain why the radiator fan keeps kicking in at high speed Does anyone know if there's a seperate fuse for this fan, how to troubleshoot it and how much replacing it would cost me Link to comment Share on other sites More sharing options...
sparky2076 Posted October 27, 2006 Report Share Posted October 27, 2006 had same prob,just repaired fan motor,brushes had worn down,the brushes r not available from vw or anywhere else that i could find,managed to find some at work and made to size work perfect.just make sure that brushes u use r from a motor that runs continuous so compound will b similar and they wont where armature out!removing motor not too bad a job and it can b got at without removing air bag which was my biggest worry.just remove glove box about 7 screws,they r torx screws but got em with small screw driver.if u need to know more repost and will try to help Link to comment Share on other sites More sharing options...
ocrp Posted October 28, 2006 Author Report Share Posted October 28, 2006 Thanks for your reply, Sparky. You are confusing the blower motor (which I have already replaced) with the cooling fan for the condenser, located in the bonnet next to the radiator. I have since taken the car in to be looked at, where typical to Murphy's law, it was working fine. What is happening is the fan is not coming on all the time at low speed, as it should, and when the system starts to heat up e.g. when the car is stationary, the fan kicks in at high speed. With these type of intermittant faults, you just need to wait until the thing fails completely before you can make an accurate diagnosis. Link to comment Share on other sites More sharing options...
mickey_forster Posted October 30, 2006 Report Share Posted October 30, 2006 I have a similar problem. Last week I jumped into car and coolant light started flashing so I topped it up. Yesterday I noticed that the electrical fan (not the belt driven one) is running nearly constantly and the car takes ages to heat up which is crap on these cold mornings. Are these two problemos linked? I must have a look to see if the fan goes off when its in Econ mode on my way home in 15 minutes (woohoo) Mick Link to comment Share on other sites More sharing options...
ocrp Posted October 31, 2006 Author Report Share Posted October 31, 2006 The electrical fan is supposed to run constantly when the aircon is running (Auto mode). It has two speeds. Normal operation should run it in slow speed. On hot days it will go to high speed (very noisy). Switching to Econ will turn it off. I doubt this has anything to do with how fast the car heats up. Link to comment Share on other sites More sharing options...
meriafel Posted November 1, 2006 Report Share Posted November 1, 2006 My 52 plate 90k sport TDi is doing the same which I've only recently been aware of. Radiator fan is running at high speed when air con on AUTO even when engine cold. Rang Inchcape, Service Manager rang back and said that it was quite normal when on auto. So, who is right? Could it be that when the car has been sitting in the sun, the interior is hotter than the chosen temperature setting in the display, requiring the fan to run, although the engine is quite cold? Does seem logical to me. My car sits in the sun on a south facing slope and despite having the factory heat absorbing tinted glass can get hot. My fan certainly goes off when ECON is selected. As the dealer didn't hesitate in his diagnosis that all is normal I've accepted it. Some time ago there was a posting that gave an address for a supplier who will make up the blower motor carbon brushes. I ordered 3 sets for £20 as they had a min charge of £20. They are the correct grade of carbon too. Will post contact details when I can find them! Link to comment Share on other sites More sharing options...
meriafel Posted November 3, 2006 Report Share Posted November 3, 2006 The company that made up the correct Passat blower motor carbon brushes was ANGLO CARBON Tel 0113 2564664. E-mail [email protected] Very helpful guys and with an excellent postal service. Link to comment Share on other sites More sharing options...
ocrp Posted November 5, 2006 Author Report Share Posted November 5, 2006 [ QUOTE ] Rang Inchcape, Service Manager rang back and said that it was quite normal when on auto. So, who is right? [/ QUOTE ] Well, as we all know, VW seems to have "acceptable parameters" for certain issues, which the general public like to describe as faults... Link to comment Share on other sites More sharing options...
meriafel Posted November 7, 2006 Report Share Posted November 7, 2006 Life is the acceptance of "acceptable parameters" for most issues and this is possibly another. There is little evidence that the cooling fan is 'overactive' or showing symptoms of a 'fault'? VW don't seem to see the cooling fan running fast, as a 'fault' and I take comfort in the fact that they would only be to eager to take my money if they could sort it. PS. The cost of £20 for Anglo Carbon Brushes was in fact for four sets not three as I stated above. Sods Law dictates that I will probably never need them for the two Passats in the family! Link to comment Share on other sites More sharing options...
Wobby Posted November 7, 2006 Report Share Posted November 7, 2006 Its doubtful, but you can always sell them on to someone on here who is after some Link to comment Share on other sites More sharing options...
brogandb7 Posted November 20, 2006 Report Share Posted November 20, 2006 I've had similar problems to the ones listed above on other vehicles I've had over the years - not just VW models. Basically what happens is as follows: When you switch the aircon to "on" it discharges a relay and this turns on the main fan in the engine compartment. This helps to cool the gas even further in the condensor and the cabin gets cooler. Some vehicles have an aircon temperature sensor inside the cabin to monitor how much it needs to cool the gas and this is why the fan may only come on for short periods of time otherwise it could be a faulty relay which only costs a few pounds to replace. If you have trouble with the cabin getting warm it could be something simple such as a faulty switch in the heating controls or possibly much worse such as a blockage in the cooling system. If there is a blockage it will need to be looked ASAP as parts of the engine may not be getting cooled properly. One tip worth noting is that if you ever have problems with the car engine getting too hot put your aircon on full and this will cause all the fans in the engine bay to activate. The extra cooling will help to get your temperature gauge back down. Link to comment Share on other sites More sharing options...
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