The 75 and ZT Owners Club Forums

The 75 and ZT Owners Club Forums (https://www.the75andztclub.co.uk/forum/index.php)
-   Technical Help Forum (https://www.the75andztclub.co.uk/forum/forumdisplay.php?f=11)
-   -   fan never works (https://www.the75andztclub.co.uk/forum/showthread.php?t=302587)

super s 2nd February 2020 20:11

fan never works
 
hello...

can someone please ensure where my problem lies???

my fan never works, i hear the motor sometimes making a buzz after shutting the engine off for 10 seconds or so.

but never see the fan acctually working...

can anyone advice me where the problem lies exaqly???

thanks to all

Yorkshire GOC 3rd February 2020 09:01

Will depend if you have a 2 speed or earlier 3 speed fan -

go to the front of the car - look through the grill to the right and see if on front of the fan to see if you have silver resistor (6cm's long) - this will indicate a 2 speed fan and if the silver resistor has failed you need to replace it with an upgraded Gold resistor (10-15 euros) - to confirm - do this

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. If not it's probably time for a new upgraded gold resistor.

https://www.dmgrs.co.uk/products/rov...64fde3e6&_ss=r

If no resistor on your fan then it is likely to be an earlier 3 speed fan and it is probably a failure of the brushes - 20 euro fix

https://www.ebay.co.uk/itm/Rover-75-...-/253458854588

Arctic 3rd February 2020 09:29

[QUOTE]
Quote:

Originally Posted by super s (Post 2790622)
hello...

can someone please ensure where my problem lies???

my fan never works, i hear the motor sometimes making a buzz after shutting the engine off for 10 seconds or so.

but never see the fan acctually working...

can anyone advice me where the problem lies exaqly???

thanks to all[/QUOT

E]

Hi Sergio.
As above first find out which fan you have by looking through the front grill at about 14.00pm, with the engine not running you can insert a long screw driver to turn the fan blade to the required position, this will allow you to use a torch shine it into the area you will see either a silver resistor.

Which is a two speed fan.
https://i.imgur.com/hYyWtBfl.jpg1

No resistor in place will be a four wire three speed fan.
https://i.imgur.com/O2TOWvGl.jpg2

To do the demist test make sure all the A/C is in the of position, turn the ignition key to II without starting the car (Diesel) then press demist button look through the front grill to see if the fan is running continually.

If the fan is not running and you have a silver resistor in place replace this with a gold one the fan should work.
https://i.imgur.com/ZUxJ7RRl.jpg3

If not working and no resistor then you need to either replace the fan, or replace the brushes in the fan motor you will not know this until the fan is removed from the car and the motor opened up.
https://i.imgur.com/mJVlCvhl.jpg4

https://i.imgur.com/L53HLWwl.jpg5

https://www.ecp.co.uk/rover75-carbon-brushes.php

RoverP480 3rd February 2020 12:18

Check that the fan has not seized & cannot turn

super s 10th February 2020 20:37

before answering want to say thanks for all the income... sorry for the time without answering but the job is taking me apart before the car... :mad::mad::mad:

the fan has the silver resistor, so its the 2 speed one...

i will replace the resistor for the gold one has the lonk above from dmgrs...

then will leave here the news...

just another question; as any of you experienced a situation where you stop the car and engine and you hear the fan motor working for a few seconds, maybe 10 seconds or so???

thanks.

T-Cut 10th February 2020 21:51

Quote:

Originally Posted by super s (Post 2790622)
my fan never works, i hear the motor sometimes making a buzz after shutting the engine off for 10 seconds or so, but never see the fan acctually working.

Hello Sergio,
You said your fan never works, however the diesel rarely needs the fan for engine cooling. The aircon system uses the low speed fan far more often, so have you confirmed it doesn't operate when the aircon is switched on? This can be checked by running the Demist Test. Realistically it's quite likely that the original resistor you see has indeed failed because they are under-powered.

Quote:

Originally Posted by super s (Post 2792358)
any of you experienced a situation where you stop the car and engine and you hear the fan motor working for a few seconds, maybe 10 seconds or so???

Are you sure this is the radiator fan motor you hear? If it buzzes but doesn't turn, then something is preventing it or perhaps the blades have separated from the motor?
If the low speed resistor has indeed failed, then you must be hearing the high speed. which is an unusual behaviour for a diesel fan. However, the diesel's control system is different from the others. It uses a printed circuit board that's known to be problematic. Strange behaviour of the diesel fan motor could suggest the circuit board needs fixing.

There seems to be several things to consider. Does the motor actually turn or is the buzzing caused by a seized bearing, etc? The low speed system will require an uprated ('Gold') resistor (forum traders, eBay, etc) which will then enable you to run more tests to verify if the circuit board is operating correctly.

TC

macafee2 10th February 2020 22:09

that buzz, does it sound like radio interference? I get this when I turn my ignition off.
For the life of me I cant recall what it is but I was told a few years ago.
Is it vents closing?

macafee2

super s 14th February 2020 18:11

ok...

i already bought the resistor from dmgrs, when i put in place i will leave info here for more informations...

however i have a feelling that is something with the fan motor itself...
or the blades have in somehow dislodge from the fan motor...

thanks to all input and help...

T-Cut 14th February 2020 18:30

Quote:

Originally Posted by super s (Post 2793169)
- - - i have a feelling that is something with the fan motor itself... or the blades have in somehow dislodge from the fan motor...

The fan blades can become detached from the motor drive flange. The central area of the plastic fan can get quite hot and eventually it may embrittle. The bayonet lugs that lock it into the drive flange sometimes break off. This can cause the blades to fall off. It would be unusual for a diesel to suffer this because the fan gets rather less use - unless the aircon's on all the time.



TC

super s 21st October 2020 14:20

well finally could find that the problem is the fan dislodge from motor itself... i have the gold resistor but now is a job of front off...

could the fan be re used or should i need another...

i believe it seized and got stuck in the plastic fan protector and while the motor turned it came out...

does this make any sence ???

or am i being a bit duff?


All times are GMT. The time now is 04:33.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd