Radiator Fan Dead?

Sledge · 3rd June 2016, 00:48

Hi All,

My 75 seems to have a dead fan. I tried some of the tests you guys have posted, eg demist test and running with climate control on and the front fan doesn't seem to spin up.

Also, at idle, the temperature seems to climb around 105C. Whilst I know this is within tolerance, I thought the fan should cut in around this temp.

Any suggestions on what to check next? What is the "gold resistor" I see floating around some posts?

thanks in advance.

Dragrad · 3rd June 2016, 00:53

Plenty of threads available on this subject in the Technical Help & How To forums

Do a search and all will be revealed

Sledge · 3rd June 2016, 01:02

I have done, hence why I am aware of things like the gold resistor and operating temps, sometimes the search terms one enters may not always find the post or threads that answer the question.

One thread I am looking at right now talks a lot about the resistor, but doesn't shed light on what it actually does or where it is.

casperdog21 · 3rd June 2016, 01:21

theres loads of threads regarding the fan and resistor, it depends on what type of fan is fitted to your car my v6 has the fan kicking in at a 100deg and cools to 94, but someone will give you all the info you require everyone in the uk is sleeping so give it a few hours

Sledge · 3rd June 2016, 02:09

Thanks casper,

I am aware of the time of night, I think we're 12 hrs ahead. As I said, the searches I found talk about specific parts but don't really help me if I am not familiar.

eg what components do I check to nail down the problem? I think there is a fusible link, a relay and this resistor that is mentioned, but I'm not sure.

anyway hope you guys enjoy your breakfast for those who are still sleeping.

Sledge · 3rd June 2016, 02:54

ok,

looking at this post:

http://www.the75andztclub.co.uk/foru...92&postcount=6

I don't have one fitted.

Fan spins freely.

T-Cut · 3rd June 2016, 09:36

Quote:

Originally Posted by Sledge

(- - resistor) I don't have one fitted.

Even a 2004 model may have the earlier 3-speed fan system. It's not possible to define it exactly. A visual examination of the motor is the only way to be sure. Also, some 2-speed models had the resistor mounted out of sight for some obscure reason, so you can never be 100% certain.

To establish which system you have means taking off the front bumper panel and checking the motor wiring. Resistor controlled (2-speed) motors have two wires entering the case. The other KV6 system (3-speed) has four.

If it is indeed a 3-speed, a replacement 2-speed will be needed or a rebrush of the old motor. If it's a 2-speed you need a replacement uprated resistor. They're easy to fit and are available from forum traders, ebay, electronics outlets, etc.

There are HowTos available for doing all the required tasks.

TC

Sledge · 3rd June 2016, 10:31

Thanks T-Cut,

My 75 is MY03 Reg May 04

I shall have a look over the weekend. Any other ideas welcome.

Sledge · 20th June 2016, 02:24

Hi all,

Sorry for bumping this thread. I have got to the point of pulling the front end off my 75, based on this post:

http://www.the75andztclub.co.uk/foru...61&postcount=1

I gather that being the V8 in the pics, the duct is specific to the V8. If taking the whole front end off, I don't have to undo the 8 bolts on the crash bar?

I've also read about the demist test.

ATM, I'm a bit hesitant to pull the front off. What I would like to know is without pulling the front off, whether there is a test point somewhere that I can stick a multimeter to check the fan motor. If there is, where is it and what sort of reading should I expect? I have found the link about the carbon brushes from ECP, but what if it's the PCB?

I'd really appreciate someone shedding some light on this before I begin the dismantle.

Thanks again in advance.

SD1too · 20th June 2016, 08:35

Quote:

Originally Posted by Sledge

... I don't have to undo the 8 bolts on the crash bar?

As far as I remember you do have to remove the 'crash bar' (which MGR calls the armature

).

Quote:

What I would like to know is without pulling the front off, whether there is a test point somewhere that I can stick a multimeter to check the fan motor.

No there isn't Rod. You have to remove the front, but it's not as bad as it sounds.

Quote:

... but what if it's the PCB?

The PCB system is found only on the diesels, so it won't be that!

Simon

3rd June 2016, 00:48	#1
Sledge Loves to post Rover 75 SE V6 2.5 Join Date: Sep 2013 Location: Durie Hill Posts: 403 Thanks: 28 Thanked 41 Times in 27 Posts	Radiator Fan Dead? Hi All, My 75 seems to have a dead fan. I tried some of the tests you guys have posted, eg demist test and running with climate control on and the front fan doesn't seem to spin up. Also, at idle, the temperature seems to climb around 105C. Whilst I know this is within tolerance, I thought the fan should cut in around this temp. Any suggestions on what to check next? What is the "gold resistor" I see floating around some posts? thanks in advance.

3rd June 2016, 00:53	#2
Dragrad This is my second home *None DROWNED** Join Date: Aug 2007 Location: Cardigan Posts: 33,339 Thanks: 1,257 Thanked 1,664 Times in 1,081 Posts	Plenty of threads available on this subject in the Technical Help & How To forums Do a search and all will be revealed __________________ Andrew Ich Dien Problem solving is... lateral thinking SEARCH FIRST ...ASK LATER...

3rd June 2016, 01:21	#4
casperdog21 Avid contributor rover 75 club se Join Date: Aug 2014 Location: sunderland Posts: 150 Thanks: 5 Thanked 5 Times in 5 Posts	theres loads of threads regarding the fan and resistor, it depends on what type of fan is fitted to your car my v6 has the fan kicking in at a 100deg and cools to 94, but someone will give you all the info you require everyone in the uk is sleeping so give it a few hours Last edited by casperdog21; 3rd June 2016 at 01:23.. Reason: missed point

3rd June 2016, 02:54	#6
Sledge Loves to post Rover 75 SE V6 2.5 Join Date: Sep 2013 Location: Durie Hill Posts: 403 Thanks: 28 Thanked 41 Times in 27 Posts	ok, looking at this post: http://www.the75andztclub.co.uk/foru...92&postcount=6 I don't have one fitted. Fan spins freely. Last edited by Sledge; 3rd June 2016 at 03:42..

3rd June 2016, 10:31	#8
Sledge Loves to post Rover 75 SE V6 2.5 Join Date: Sep 2013 Location: Durie Hill Posts: 403 Thanks: 28 Thanked 41 Times in 27 Posts	Thanks T-Cut, My 75 is MY03 Reg May 04 I shall have a look over the weekend. Any other ideas welcome. Last edited by Sledge; 3rd June 2016 at 10:34..

3rd June 2016, 01:02	#3
Sledge Loves to post Rover 75 SE V6 2.5 Join Date: Sep 2013 Location: Durie Hill Posts: 403 Thanks: 28 Thanked 41 Times in 27 Posts	I have done, hence why I am aware of things like the gold resistor and operating temps, sometimes the search terms one enters may not always find the post or threads that answer the question. One thread I am looking at right now talks a lot about the resistor, but doesn't shed light on what it actually does or where it is.

3rd June 2016, 02:09	#5
Sledge Loves to post Rover 75 SE V6 2.5 Join Date: Sep 2013 Location: Durie Hill Posts: 403 Thanks: 28 Thanked 41 Times in 27 Posts	Thanks casper, I am aware of the time of night, I think we're 12 hrs ahead. As I said, the searches I found talk about specific parts but don't really help me if I am not familiar. eg what components do I check to nail down the problem? I think there is a fusible link, a relay and this resistor that is mentioned, but I'm not sure. anyway hope you guys enjoy your breakfast for those who are still sleeping.

20th June 2016, 02:24	#9
Sledge Loves to post Rover 75 SE V6 2.5 Join Date: Sep 2013 Location: Durie Hill Posts: 403 Thanks: 28 Thanked 41 Times in 27 Posts	Hi all, Sorry for bumping this thread. I have got to the point of pulling the front end off my 75, based on this post: http://www.the75andztclub.co.uk/foru...61&postcount=1 I gather that being the V8 in the pics, the duct is specific to the V8. If taking the whole front end off, I don't have to undo the 8 bolts on the crash bar? I've also read about the demist test. ATM, I'm a bit hesitant to pull the front off. What I would like to know is without pulling the front off, whether there is a test point somewhere that I can stick a multimeter to check the fan motor. If there is, where is it and what sort of reading should I expect? I have found the link about the carbon brushes from ECP, but what if it's the PCB? I'd really appreciate someone shedding some light on this before I begin the dismantle. Thanks again in advance.