Cooling fan - running on after switch off.

Tetleysmooth · 28th October 2022, 14:13

Hi all. My car is an October 2004 Connoiseur 1.8 non turbo.
If I do a longer than average run, my cooling fan continues to run after I've switched the ignition off. I can normally stop it by switching the ignition on, then off again, however, it took a couple of times to do this yesterday.
The chap I bought the car from was very upfront about it, and in his own words, 'one of the resistors has snuffed it'.
Is this correct? If so, where can I get said resistor? Is it an easy job? I haven't bought a Haynes for it yet.
Help much appreciated. Thanks in advance.

FLYING BANANA · 28th October 2022, 14:19

On mine it was a faulty relay that sits behind the fan. I had a garage do the job as it’s a bumper off to get to it.

Yorkshire GOC · 28th October 2022, 14:58

Quote:

Originally Posted by Tetleysmooth

Hi all. My car is an October 2004 Connoiseur 1.8 non turbo.
If I do a longer than average run, my cooling fan continues to run after I've switched the ignition off. I can normally stop it by switching the ignition on, then off again, however, it took a couple of times to do this yesterday.
The chap I bought the car from was very upfront about it, and in his own words, 'one of the resistors has snuffed it'.
Is this correct? If so, where can I get said resistor? Is it an easy job? I haven't bought a Haynes for it yet.
Help much appreciated. Thanks in advance.

Assuming you have a 2 speed fan (as opposed to the three speed one which does not have a resistor on the fan face)from what the previous owner said - when you look at your fan through the grill - at 2 o clock on the fan there is a resistor - originally silver in colour - these are a known fail point -so folk replace them with the upgraded gold resistor -

See link below -from DMGRS

https://www.dmgrs.co.uk/products/rov...airs-pgj000110

Tetleysmooth · 28th October 2022, 15:10

Is that do-able without bumper removal?

Yorkshire GOC · 28th October 2022, 15:22

No - fraid its bumper off.

Yorkshire GOC · 28th October 2022, 15:26

But as the DMGRS site advises do the demist test to satisfy yourself whether the resistor is working or not - see 5th post in on link below.

https://the75andztclub.co.uk/forum/s...d.php?t=249845

Tetleysmooth · 28th October 2022, 19:08

Well, if the resistor is borked, it looks like it'll have to wait. Not only have I not got a Haynes yet, I've never soldered anything in my life. Thanks for the help. I will try that test though.

stocktake · 28th October 2022, 19:48

The situation you are describing is NOT the resistor. A fan running on after ign off is usually the overheat setting, it could also be a sticking relay.

There are a number of issues that cause the fan to run:

1. Loss of signal from the temp sender (only when ign on)
2. Relay stuck in energised position (even when key removed)
3. Engine overheat detected (fan remains on when key removed)

you need to access the on board diagnostics to find out the actual temp.

https://www.youtube.com/watch?v=VXhpxZH1W2Y

Tetleysmooth · 28th October 2022, 21:05

I've had the car about three weeks now, and if it's anything to go by, the temp guage never goes above halfway. The car runs very well too. Doesn't use oil or coolant. This has got me scratching my head now.

stocktake · 28th October 2022, 21:29

Quote:

Originally Posted by Tetleysmooth

I've had the car about three weeks now, and if it's anything to go by, the temp guage never goes above halfway. The car runs very well too. Doesn't use oil or coolant. This has got me scratching my head now.

Temp gauge is useless. stays at halfway between 75 and 115 degrees by design, well documented on here. access the on board diagnostice as per the link in my previous post

28th October 2022, 14:13	#1
Tetleysmooth Regular poster Rover 75 saloon Join Date: Oct 2022 Location: Rainham Posts: 36 Thanks: 1 Thanked 2 Times in 1 Post	Cooling fan - running on after switch off. Hi all. My car is an October 2004 Connoiseur 1.8 non turbo. If I do a longer than average run, my cooling fan continues to run after I've switched the ignition off. I can normally stop it by switching the ignition on, then off again, however, it took a couple of times to do this yesterday. The chap I bought the car from was very upfront about it, and in his own words, 'one of the resistors has snuffed it'. Is this correct? If so, where can I get said resistor? Is it an easy job? I haven't bought a Haynes for it yet. Help much appreciated. Thanks in advance.

28th October 2022, 14:19	#2
FLYING BANANA Moderator/Club Shop MG ZT 1.8t+. No.3 of 4 in Sunspot Yellow & Ford Fiesta in Black. Join Date: Aug 2010 Location: Rattler Farm Posts: 22,652 Thanks: 9,270 Thanked 15,645 Times in 6,806 Posts	On mine it was a faulty relay that sits behind the fan. I had a garage do the job as it’s a bumper off to get to it. __________________ 234,303. onen hag oll

28th October 2022, 15:22	#5
Yorkshire GOC I really should get out more....... Rover 75 connoisseur se v6 auto Join Date: May 2014 Location: Hull Posts: 2,086 Thanks: 1,842 Thanked 623 Times in 469 Posts	No - fraid its bumper off. __________________ She came off the Longbridge Line on 20-05-2003 The Silver Machine was the 13th of 160 Rover 75's to come off the production line that day and is the 100th of 527 Starlight Silver Rover 75 2.5 V6 Connoisseur SE Auto saloons listed in the build records produced world wide.

28th October 2022, 15:26	#6
Yorkshire GOC I really should get out more....... Rover 75 connoisseur se v6 auto Join Date: May 2014 Location: Hull Posts: 2,086 Thanks: 1,842 Thanked 623 Times in 469 Posts	But as the DMGRS site advises do the demist test to satisfy yourself whether the resistor is working or not - see 5th post in on link below. https://the75andztclub.co.uk/forum/s...d.php?t=249845 __________________ She came off the Longbridge Line on 20-05-2003 The Silver Machine was the 13th of 160 Rover 75's to come off the production line that day and is the 100th of 527 Starlight Silver Rover 75 2.5 V6 Connoisseur SE Auto saloons listed in the build records produced world wide.

28th October 2022, 19:48	#8
stocktake Vis Whiz Rover 75 2.5 auto Saloon Join Date: Jun 2007 Location: LEEDS Posts: 20,604 Thanks: 2,057 Thanked 3,056 Times in 1,621 Posts	The situation you are describing is NOT the resistor. A fan running on after ign off is usually the overheat setting, it could also be a sticking relay. There are a number of issues that cause the fan to run: 1. Loss of signal from the temp sender (only when ign on) 2. Relay stuck in energised position (even when key removed) 3. Engine overheat detected (fan remains on when key removed) you need to access the on board diagnostics to find out the actual temp. https://www.youtube.com/watch?v=VXhpxZH1W2Y __________________ Dave... Lost a few stones and a Gall Bladder and part of a bile duct and all of my dignity in the suppository incident

28th October 2022, 15:10	#4
Tetleysmooth Regular poster Rover 75 saloon Join Date: Oct 2022 Location: Rainham Posts: 36 Thanks: 1 Thanked 2 Times in 1 Post	Is that do-able without bumper removal?

28th October 2022, 19:08	#7
Tetleysmooth Regular poster Rover 75 saloon Join Date: Oct 2022 Location: Rainham Posts: 36 Thanks: 1 Thanked 2 Times in 1 Post	Well, if the resistor is borked, it looks like it'll have to wait. Not only have I not got a Haynes yet, I've never soldered anything in my life. Thanks for the help. I will try that test though.

28th October 2022, 21:05	#9
Tetleysmooth Regular poster Rover 75 saloon Join Date: Oct 2022 Location: Rainham Posts: 36 Thanks: 1 Thanked 2 Times in 1 Post	I've had the car about three weeks now, and if it's anything to go by, the temp guage never goes above halfway. The car runs very well too. Doesn't use oil or coolant. This has got me scratching my head now.