Fan operation with Aircon running

bear-mg · 16th July 2020, 20:35

Just after some advice, am I right in thinking that when the Aircon is running the fan should be running constantly in the lower speed? My fan appears to just cut in every so many seconds in high speed... I've had a look through the grill and it appears to of had an updated resistor fitted at some stage in its life , could this need replacing again? It's a 2004 cdti ... cheers 👍

SD1too · 16th July 2020, 20:51

Quote:

Originally Posted by bear-mg

... am I right in thinking that when the Aircon is running the fan should be running constantly in the lower speed?

Yes.

Quote:

Originally Posted by bear-mg

My fan appears to just cut in every so many seconds in high speed... it appears to of had an updated resistor fitted at some stage in its life , could this need replacing again?

Yes again!

Simon

bear-mg · 16th July 2020, 22:07

Quote:

Originally Posted by SD1too

Yes.

Yes again!

Simon

Excellent 😂👍

Yorkshire GOC · 17th July 2020, 12:23

My upgraded gold resistor on my 2 speed lasted 5 and half years
- replaced last year.

bear-mg · 17th July 2020, 16:59

Quote:

Originally Posted by Yorkshire GOC

My upgraded gold resistor on my 2 speed lasted 5 and half years
- replaced last year.

Just ordered a new resistor 👍👍

Chunky2778 · 17th July 2020, 19:59

My fan only cuts in on high speed when AC on, it's an early facelift I think (04), sounds like a hovercraft starting up.

Would this need a resistor too please, if so which ones the best to get?

SD1too · 17th July 2020, 20:04

Quote:

Originally Posted by Chunky2778

My fan only cuts in on high speed when AC on ... sounds like a hovercraft starting up.

Hello Matt,

The tell-tale sign of resistor failure is that the high speed pulses on and off every few seconds as bear-mg described. If your fan is running continuously it's probably o.k. The 2 speed system can be very noisy!

Simon

Chunky2778 · 17th July 2020, 20:10

Quote:

Originally Posted by SD1too

Hello Matt,

The tell-tale sign of resistor failure is that the high speed pulses on and off every few seconds as bear-mg described. If your fan is running continuously it's probably o.k. The 2 speed system can be very noisy!

Simon

Ah ok thanks, sounds like mine is ok then.

bear-mg · 19th July 2020, 19:37

Quote:

Originally Posted by Chunky2778

My fan only cuts in on high speed when AC on, it's an early facelift I think (04), sounds like a hovercraft starting up.

Would this need a resistor too please, if so which ones the best to get?

Sounds like the resistor at fault 👍

Yorkshire GOC · 20th July 2020, 15:27

Quote:

Originally Posted by Chunky2778

Ah ok thanks, sounds like mine is ok then.

To be absolutely sure do the D Mist test

Start from cold. Put air con to "ECON" and turn on front screen demist. Nip round the front and have a look through the grille to see if the fan is permanently turning(you should hear it). It should be running at low speed if not it's probably time for a new resistor - the upgraded gold version which you can get on e bay.

16th July 2020, 20:35	#1
bear-mg Loves to post mg zt cdti 160👍 Join Date: Jun 2014 Location: bath Posts: 374 Thanks: 105 Thanked 50 Times in 43 Posts	Fan operation with Aircon running Just after some advice, am I right in thinking that when the Aircon is running the fan should be running constantly in the lower speed? My fan appears to just cut in every so many seconds in high speed... I've had a look through the grill and it appears to of had an updated resistor fitted at some stage in its life , could this need replacing again? It's a 2004 cdti ... cheers 👍

17th July 2020, 12:23	#4
Yorkshire GOC I really should get out more....... Rover 75 connoisseur se v6 auto Join Date: May 2014 Location: Hull Posts: 2,067 Thanks: 1,842 Thanked 623 Times in 469 Posts	My upgraded gold resistor on my 2 speed lasted 5 and half years - replaced last year. __________________ 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.

17th July 2020, 19:59	#6
Chunky2778 Avid contributor MG ZT Join Date: Mar 2019 Location: Plymouth Posts: 109 Thanks: 5 Thanked 9 Times in 8 Posts	My fan only cuts in on high speed when AC on, it's an early facelift I think (04), sounds like a hovercraft starting up. Would this need a resistor too please, if so which ones the best to get?