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rover_75
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Discussion Starter · #1 ·
Sorry to bring up an old subject but whilst doing the intake mod i had a thought, yes I do occasionally have them. I have never known or heard the radiator fan come on. So I went out for a run in the car after doing the mod and got the car up to temp and left it to run for a few mins (I know it probably wasn’t enough but im impatient). So my question is when should the fan come on should it come on when the air con is on and im at a standstill (sure it doesn’t, although once moving the aircon is icy cold). How urgent is it to get sorted, ive had the car 4 months and if it isn’t working now I don’t think it has ever worked. Oh she (touch wood) has had no probs with overheating in the middle all the time.
As I say im sorry to bring this up again but the old posts didn’t say how to diagnose if the fan doesn’t or does work. oh its a 2.0 cdt con
 

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other_manufacturer
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With your air con set to AUTO, the fan will be on constantly, no matter what temp the engine is.

Urgent? Very!

Especially with the warmer weather heading in, one traffic jam = HGF!
 

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RichK said:
With your air con set to AUTO, the fan will be on constantly, no matter what temp the engine is.

Urgent? Very!

Especially with the warmer weather heading in, one traffic jam = HGF!
Not sure about my 75 but in my previous 420 Sdi, I never once had the temp gauge go higher than normal in 7 years when stood in traffic, hence the fan never came on. Come to think of it I cant recall the fan ever running.

Is this because its a diesel?
 

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rover_75_tourer
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Had my 75 Diesel tourer a few weeks now .

When Air Con is switched on , the radiator fan starts straight away , you'll hear it OK !! , this has no connection with engine temperature.

I think you have a problem . SMC sell fan motor and relay for £99 on eb*y!


On my other car (diesel VW Sharan ) and in common with most diesels the engine cooling fan hardly comes on at all! These diesels seem to cope with higher temperature with more capability than a petrol.

Also - even if fan is NOT turning , when you drive along the air con will appear to be very cold ! Be warned !

Hope this helps.
 

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rover_75
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Discussion Starter · #6 ·
anybody know how to remove the relays from the engine fuse box so i can see if my fan probleb is a relay fault or a motor fault
thanks
 

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Fuses

josef said:
anybody know how to remove the relays from the engine fuse box so i can see if my fan probleb is a relay fault or a motor fault
thanks
As far as I know the 'engine fuse box' only contains a fuse for the heater fan not the air con fan. If you follow the wires (in corrogated tube) from the fan you will find the control box that contains the relays
 

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other_manufacturer
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Checkout the "How To" forum, there's instructions in there which help you avoid having to disconnect the air con gas pipes.
 

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mg_zt
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I'm about to have my 3rd engine cooling fan fitted to my 04 ZT CDTi. It has done 60k but that is no excuse. Not an uncommon problem it would seem. Dealer has promised to look a bit deeper into the problem as this one was only fitted in October last year. I'll keep you posted if they find anything.
 

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Rover 75 Fan Problems

I recently had some work done on the climate control in my Rover 75 Diesel inlcuding regassing. Whilst he was carrying out the work he noted that the fan was not coming on when the cc was on auto, plus there are some funny noises emanating from the cc and changes in revs when in traffic. Looking at the other threads in the forum it would appear to be the fan relay and Apple Developments have quoted me up to £460 - eeek!! So I'm considering replacing it myself asisted by Will's excellent 'how to' thread but have a few questions;
- SMC on ebay are offering a cooling fan motor (4645580522) is this all I need?
- SMC mention that the wiring might need to be replaced depending on model, is this likely and is it a big job?
- Apple made mention of a modification that may need to be done, does anyone know what they might be referring to?
 

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rover_75
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Radiator fan

Hi everybody. Joined the forum last week but have been unable as of yet to post. Got my 1999 CDT Club SE in August 2004 from a private sale. Some 30,000 miles later the second Fan Assembly (FA) fitted has just failed again!
I’ve an electrical background and dug out the parts from the first unit. This modified unit has only 2 speeds and when working properly appears to switch from low to full speed when the AC system or engine demands more cooling. Thus when the low speed fails the fan pulses to full speed 5 to 6 times a minute; it also indicates the fan might not be faulty. I found the large resistor which was switched in series to the fan for low speed was open circuit. I checked the same one on my car this weekend and it too now is open circuit. . I replaced it with a larger power handling resistor and the fan is now working on Low Speed. (actually a bit too low as my guess of the resistors value was a tad too high). So problem has been solved. It is clear there is a design fault in the FA because the original resistor would only have been able to handle the power, (I estimate to be about 100 watts) if its heatsink it was mounted directly to a metal surface. To rectify this I’ve modified the wiring to allow the new resistor to bolted on to the MAF Spray deflection panel just under the slam panel and more importantly just behind the radiator grill so that I can fit the correct value resistor when it arrives. (hopefully this weekend) and /or replace it if it goes again. Cost of Resistor about £10 (inc post and packing) and £25 for a new soldering iron (mine was not big enough.) A lot cheaper than the £550 being quoted.
 

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Phil72 said:
I- SMC on ebay are offering a cooling fan motor (4645580522) is this all I need?
- SMC mention that the wiring might need to be replaced depending on model, is this likely and is it a big job??
i bought one for my 75 cdt it was s simple case of using the new motor and your existing wires i had mine done by an auto lecas i didnt have time, however if you know what your doing its a simple job with patience.
 
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