Radiator cooling fan

frankgoldstar · 23rd June 2017, 11:46

Dear all,

I am trying to find a definitive answer to the old 3 speed fan to 2 speed fan issue.

My fan (2002 CDT) failed last week in the hot weather, so I started looking at the info on this esteemed website.

There is a lot of it, but the bit that puzzled me is I do not see a definitive answer in simple terms as to how I can fit a 2 speed PMW controlled fan to my car, which has the old 3 speed, relay controlled fan fitted.

I have seen such phrases as "plug and play", but no detail to support that assertion.

I have also seen a rather detailed but still difficult to understand procedure for chopping wires around to fit a petrol fan to a diesel.

I am seeking some clarity here, so can I ask the assembled wise ones two questions:

1.Can a 2 speed fan from a late CDTI be fitted to a 2002 CDT equipped with an old style 3 speed fan?

2. If the answer is yes, exactly how is this achieved?

Excuse my ignorance here, but I have been confused by a plethora of information on what seems be a complex subject. Especially as the 75 seems to have had more fans than a football team.

T-Cut · 23rd June 2017, 11:50

Yes it can, but the complete fan system, including the frame guard with it's attached control box must be with it. The connectors from the replacement system plug into the connectors at the nearside wing area.

The resistor should be upgraded to the 100w 'gold' type if it's not already done.You can get these ready to connect in from forum traders, from eBay or as a complete DIY job from electronics outlets, Maplin, etc

TC

frankgoldstar · 23rd June 2017, 13:21

Many thanks for that T-Cut.

At last, a clear reply so I can reserve the fan assembly I saw on a recent recreational visit to a local scrapyard.

I know what I am doing this weekend!

Best wishes, Frank

SD1too · 23rd June 2017, 16:49

Frank; here are a few more facts which might assist with your decision making.

Quote:

Originally Posted by frankgoldstar

My fan (2002 CDT) failed last week in the hot weather ..

This being so, you have the option of renewing the one (or at the most, two) motor brushes which is the cause of the failure. It's the most economical solution for the keen DIY-er.

Quote:

.. how I can fit a 2 speed PMW controlled fan to my car, which has the old 3 speed, relay controlled fan fitted.

Both the 2 and 3 speed diesel fans are PWM controlled and both have relays too.

Simon

frankgoldstar · 24th June 2017, 16:22

Thanks for the additional info.

I thought it best to just change the fan as I had already spotted an 06 diesel in a nearby scrappers.

As this must be the oldest 3 speed still running (forget exact figure, but the car has 170-180k on the clock) and for a modest outlay, I thought I could hopefully obviate any future problems for the life of the car.

TC was kind enough to give me a simple answer as to whether a newer fan could be easily fitted, so I went and got the fan, cowling, control box and associated wiring.

The only thing that puzzles me is that I found a pdf describing changes to the wiring needed to fit the fan, but as I understood TC, I only have to plug it and replace the resistor too.

And also thanks for telling me they are both PWM controlled. I was puzzled by some of the stuff I read from people who actually know what they are doing!

I will find out tomorrow for if it all works out for sure. If I screw up, expect more anguished wailing and abject pleas for help!

Best wishes, Frank

T-Cut · 24th June 2017, 17:14

Quote:

Originally Posted by frankgoldstar

I will find out tomorrow for if it all works out for sure. If I screw up, expect more anguished wailing and abject pleas for help!

Hello again Frank,
This HowTo might provide some assistance: https://the75andztclub.co.uk/forum/s...ad.php?t=86328

I dont think you'll have any problems (- - he said with fingers crossed).

EDIT: Check the condition of the aircon condenser fins. After the considerable mileage you mention, the fins may well be hanging onto the thing by static electricity.

TC

frankgoldstar · 24th June 2017, 22:40

Dear TC,

thanks for the link to the great guide for some of essentials the upcoming job.

Info like this is brilliant and a credit to all the great people, your self included of course, who make having a Rover more than just owning a car.

I did think about the condenser and mine is probably shot. However, since the aircon leaks like a sieve (tried regassing, shame about that) and does not work, I will live with it as it is.

Best wishes, Frank B

23rd June 2017, 11:46	#1
frankgoldstar Avid contributor Rover 75 Conny Saloon Join Date: Sep 2009 Location: Manchester Posts: 144 Thanks: 16 Thanked 25 Times in 16 Posts	Radiator cooling fan Dear all, I am trying to find a definitive answer to the old 3 speed fan to 2 speed fan issue. My fan (2002 CDT) failed last week in the hot weather, so I started looking at the info on this esteemed website. There is a lot of it, but the bit that puzzled me is I do not see a definitive answer in simple terms as to how I can fit a 2 speed PMW controlled fan to my car, which has the old 3 speed, relay controlled fan fitted. I have seen such phrases as "plug and play", but no detail to support that assertion. I have also seen a rather detailed but still difficult to understand procedure for chopping wires around to fit a petrol fan to a diesel. I am seeking some clarity here, so can I ask the assembled wise ones two questions: 1.Can a 2 speed fan from a late CDTI be fitted to a 2002 CDT equipped with an old style 3 speed fan? 2. If the answer is yes, exactly how is this achieved? Excuse my ignorance here, but I have been confused by a plethora of information on what seems be a complex subject. Especially as the 75 seems to have had more fans than a football team.

23rd June 2017, 11:50	#2
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,752 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Yes it can, but the complete fan system, including the frame guard with it's attached control box must be with it. The connectors from the replacement system plug into the connectors at the nearside wing area. The resistor should be upgraded to the 100w 'gold' type if it's not already done.You can get these ready to connect in from forum traders, from eBay or as a complete DIY job from electronics outlets, Maplin, etc TC Last edited by T-Cut; 23rd June 2017 at 11:53..

23rd June 2017, 13:21	#3
frankgoldstar Avid contributor Rover 75 Conny Saloon Join Date: Sep 2009 Location: Manchester Posts: 144 Thanks: 16 Thanked 25 Times in 16 Posts	Thanks a million Many thanks for that T-Cut. At last, a clear reply so I can reserve the fan assembly I saw on a recent recreational visit to a local scrapyard. I know what I am doing this weekend! Best wishes, Frank

24th June 2017, 16:22	#5
frankgoldstar Avid contributor Rover 75 Conny Saloon Join Date: Sep 2009 Location: Manchester Posts: 144 Thanks: 16 Thanked 25 Times in 16 Posts	Cooling fan options Thanks for the additional info. I thought it best to just change the fan as I had already spotted an 06 diesel in a nearby scrappers. As this must be the oldest 3 speed still running (forget exact figure, but the car has 170-180k on the clock) and for a modest outlay, I thought I could hopefully obviate any future problems for the life of the car. TC was kind enough to give me a simple answer as to whether a newer fan could be easily fitted, so I went and got the fan, cowling, control box and associated wiring. The only thing that puzzles me is that I found a pdf describing changes to the wiring needed to fit the fan, but as I understood TC, I only have to plug it and replace the resistor too. And also thanks for telling me they are both PWM controlled. I was puzzled by some of the stuff I read from people who actually know what they are doing! I will find out tomorrow for if it all works out for sure. If I screw up, expect more anguished wailing and abject pleas for help! Best wishes, Frank

24th June 2017, 22:40	#7
frankgoldstar Avid contributor Rover 75 Conny Saloon Join Date: Sep 2009 Location: Manchester Posts: 144 Thanks: 16 Thanked 25 Times in 16 Posts	Dear TC, thanks for the link to the great guide for some of essentials the upcoming job. Info like this is brilliant and a credit to all the great people, your self included of course, who make having a Rover more than just owning a car. I did think about the condenser and mine is probably shot. However, since the aircon leaks like a sieve (tried regassing, shame about that) and does not work, I will live with it as it is. Best wishes, Frank B