Cooling Fan Problem

DJW · 7th April 2008, 19:35

I have just noticed that my cooling fan has started to run continuously. With the ignition on, climate control on. Turn the climate control off, fan off. The engine is cold.Is this a common symptom of the resistor problem I have read about?
I would say that it is running at a higher speed rather than a lower one.
Any help greatly appreciated.

I have just read this and it applies to my problem
http://www.the75andztclub.co.uk/foru...ead.php?t=1371

Aircon behaviour and Ambient Temperatures,
It was originally believed that when Aircon was selected the fan always came on at the lowest speed this is not correct and operation is determined by the temperature difference between the chosen ATC setting and the outside temperature if that difference with an outside temp of 12.5 degrees is more than approx 10 degrees C than fan will not run. 10 degrees here is used as an example as this value may increase dependant on outside temp i.e at zero degrees the difference may be even higher.

E.g
It is +12.5 in my car at the moment
I stepped my AC up from my normal 20 degrees (car is a CDT so no need for engine running) when it got to 23 degrees fan stopped step back down again and fan restarts at 21 degrees.

Absolutely brilliant, my panic was due to some strange electrical tinkering that I was in the middle of when it happened.

T-Cut · 7th April 2008, 20:05

It sounds sort of normal to me. Whether you have the 2-speed (resistor) version or the earlier 3-speed one will depend on the year. The later (resistor) type can be observed through the front grill/behind the fan blades. Look at the 2 o'clock position for the aluminium resistor screwed to the plastic bracket.

'Strange electrical tinkering'...?

TC

DJW · 7th April 2008, 20:10

I had something connected that shouldn't be! With the ignition on.

JohnDotCom · 7th April 2008, 20:31

If the Air Con is turned on the fan will run Continuously on the Diesel Models.
This is perfectly normal.
If Fan running at high speed, (it will be noisy if it is) contact Jules for a Resistor kit to Cure it.

DJW · 7th April 2008, 20:35

I didn't have the engine running just the ignition on and it wasn't running to start with. Then it started to and if you see the bit I have pasted above I found that if you fiddle around with the temperature settings it will switch off.
Because I was fiddling around with stuff I was worried something untoward may have happened.

JohnDotCom · 7th April 2008, 20:37

Should have been more Precise,
The Fan comes on and Runs on Diesels with Ignition on
Engine does not require to be running.

This only applies to DIESEL Cars with Air Con or Climate Control switched on.

If when fiddling you have hit the Econ button this would have turned it off,
or if you turned off the Controls completely.

T-Cut · 7th April 2008, 21:11

Quote:

Originally Posted by DJW

I had something connected that shouldn't be! With the ignition on.

Is it something you can tell us about?

BTW, what year is your car?

TC

DJW · 7th April 2008, 21:23

My car is a 53 plate. I am sending you a PM

7th April 2008, 19:35	#1
DJW Avid contributor MG ZT CDTI, MG ZT 160+ Join Date: Mar 2008 Posts: 129 Thanks: 0 Thanked 0 Times in 0 Posts	Cooling Fan Problem I have just noticed that my cooling fan has started to run continuously. With the ignition on, climate control on. Turn the climate control off, fan off. The engine is cold.Is this a common symptom of the resistor problem I have read about? I would say that it is running at a higher speed rather than a lower one. Any help greatly appreciated. I have just read this and it applies to my problem http://www.the75andztclub.co.uk/foru...ead.php?t=1371 Aircon behaviour and Ambient Temperatures, It was originally believed that when Aircon was selected the fan always came on at the lowest speed this is not correct and operation is determined by the temperature difference between the chosen ATC setting and the outside temperature if that difference with an outside temp of 12.5 degrees is more than approx 10 degrees C than fan will not run. 10 degrees here is used as an example as this value may increase dependant on outside temp i.e at zero degrees the difference may be even higher. E.g It is +12.5 in my car at the moment I stepped my AC up from my normal 20 degrees (car is a CDT so no need for engine running) when it got to 23 degrees fan stopped step back down again and fan restarts at 21 degrees. *Absolutely brilliant, my panic was due to some strange electrical tinkering that I was in the middle of when it happened. Last edited by DJW; 7th April 2008 at 19:54.. Reason: new information*

7th April 2008, 20:05	#2
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	It sounds sort of normal to me. Whether you have the 2-speed (resistor) version or the earlier 3-speed one will depend on the year. The later (resistor) type can be observed through the front grill/behind the fan blades. Look at the 2 o'clock position for the aluminium resistor screwed to the plastic bracket. 'Strange electrical tinkering'...? TC Last edited by T-Cut; 7th April 2008 at 20:08..

7th April 2008, 20:10	#3
DJW Avid contributor MG ZT CDTI, MG ZT 160+ Join Date: Mar 2008 Posts: 129 Thanks: 0 Thanked 0 Times in 0 Posts	I had something connected that shouldn't be! With the ignition on.

7th April 2008, 20:31	#4
JohnDotCom * Rover 75 FaceLift Tourer CDTi 170BHP Auto ConnSE 2005 Model Starlight Silver Join Date: Nov 2006 Location: Abergele Posts: 28,735 Thanks: 0 Thanked 6 Times in 5 Posts	If the Air Con is turned on the fan will run Continuously on the Diesel Models. This is perfectly normal. If Fan running at high speed, (it will be noisy if it is) contact Jules for a Resistor kit to Cure it.

7th April 2008, 20:35	#5
DJW Avid contributor MG ZT CDTI, MG ZT 160+ Join Date: Mar 2008 Posts: 129 Thanks: 0 Thanked 0 Times in 0 Posts	I didn't have the engine running just the ignition on and it wasn't running to start with. Then it started to and if you see the bit I have pasted above I found that if you fiddle around with the temperature settings it will switch off. Because I was fiddling around with stuff I was worried something untoward may have happened.

7th April 2008, 20:37	#6
JohnDotCom * Rover 75 FaceLift Tourer CDTi 170BHP Auto ConnSE 2005 Model Starlight Silver Join Date: Nov 2006 Location: Abergele Posts: 28,735 Thanks: 0 Thanked 6 Times in 5 Posts	Should have been more Precise, The Fan comes on and Runs on Diesels with Ignition on Engine does not require to be running. This only applies to DIESEL Cars with Air Con or Climate Control switched on. If when fiddling you have hit the Econ button this would have turned it off, or if you turned off the Controls completely.

7th April 2008, 21:23	#8
DJW Avid contributor MG ZT CDTI, MG ZT 160+ Join Date: Mar 2008 Posts: 129 Thanks: 0 Thanked 0 Times in 0 Posts	My car is a 53 plate. I am sending you a PM