cooling fan Motor question

[john71180]

Hi
From reading lots of info on the forum I think that my fan is not working as it should.
I have a 75 CDT
I first noticed a loud strange noise coming from under the bonnet like a school of whales. This would come and go at irregular intervals.
Next was a clicking noise like that of a relay going on and off from behind the dash.
I checked if the fan came on at low speed when the Climate control was set to Auto, it did not move.
The fan used to over run some moments after switching off but this does not happen any more.

I have found out that if i swithch the aircon off everything seems to be normal, no clicking or sounds of whales coming from under the bonnet.

It looks like i need a new motor or a spare brush for my old one.

Is there only one availiable model for the CDT with aircon ( 3 speed ) or did this change to a 2 speed fan? The reason i ask is that i would like to change one for one and just connect the wiring up, ie red to red , black to black. I am rubbish at electrics and just have not got a scooby do.


Will running the car in it's present state leaving the aircon off cause problems in the short term???

Any advice welcome
Thanks
John

[paulmariner]

Hi
From reading lots of info on the forum I think that my fan is not working as it should.
I have a 75 CDT
I first noticed a loud strange noise coming from under the bonnet like a school of whales. This would come and go at irregular intervals.
Next was a clicking noise like that of a relay going on and off from behind the dash.
I checked if the fan came on at low speed when the Climate control was set to Auto, it did not move.
The fan used to over run some moments after switching off but this does not happen any more.

I have found out that if i swithch the aircon off everything seems to be normal, no clicking or sounds of whales coming from under the bonnet.

It looks like i need a new motor or a spare brush for my old one.

Is there only one availiable model for the CDT with aircon ( 3 speed ) or did this change to a 2 speed fan? The reason i ask is that i would like to change one for one and just connect the wiring up, ie red to red , black to black. I am rubbish at electrics and just have not got a scooby do.


Will running the car in it's present state leaving the aircon off cause problems in the short term???

Any advice welcome
Thanks
John

Hi John,

I'm no expert, I just love driving my CDT!
I've got exactly the same problem, apparently it's not unusual for these cars. Reading this site has allowed me to at least understand what's happening.
The fan, if dud, obvioulsy does not do the job it should and the cooling comes from being "on the move", if you stop the noises begin because the cooling stops.
The car will suffer no obvious ill effects and the air con still works, albeit you have to be moving. It's an expensive repair by all accounts so it's that old "balance" again; do I get it done (at large cost) or does the occasional whale in the car matter?

I choose the whale!

pm

[john71180]

Hi Paul
Thanks for the advice. I would like the problem fixed but as you say it is a question of cost. Will try to source a second hand unit first.
PS i've sent you a private message
John

[JohnDotCom]

Don't Buy from the Dealers go to SMC (sell through EBay to) as they have them Lots cheaper. http://cgi.ebay.co.uk/Rover-75-MG-ZT-Cooling-Fan-Motor-NEW-A3_W0QQitemZ4645580522QQihZ002QQcategoryZ10414QQcm dZViewItem then follow "How To" to change it and do wiring.

[baxlin]

Hi
Will running the car in it's present state leaving the aircon off cause problems in the short term???
Thanks
John

Don't forget that the same fan also comes on to cool the engine. This time of year it may not be a problem, but when mine wasn't working last summer, the engine temp shot up a couple of times well into the red, with (at least) short term loss of power.

Also, I understand that the aircon components will have to work that much harder, causing pressure problems. (Am I right on this last point, gurus?)

Either way, I'd get it repaired sooner rather than later, certainly before the hotter weather is upon us.

DIY job, took me about 3-4 hours, there's a good how-to on here, maybe also on the .org site.

Malcolm

[SMC Trading]

Hi
From reading lots of info on the forum I think that my fan is not working as it should.
I have a 75 CDT
I first noticed a loud strange noise coming from under the bonnet like a school of whales. This would come and go at irregular intervals.
Next was a clicking noise like that of a relay going on and off from behind the dash.
I checked if the fan came on at low speed when the Climate control was set to Auto, it did not move.
The fan used to over run some moments after switching off but this does not happen any more.

I have found out that if i swithch the aircon off everything seems to be normal, no clicking or sounds of whales coming from under the bonnet.

It looks like i need a new motor or a spare brush for my old one.

Is there only one availiable model for the CDT with aircon ( 3 speed ) or did this change to a 2 speed fan? The reason i ask is that i would like to change one for one and just connect the wiring up, ie red to red , black to black. I am rubbish at electrics and just have not got a scooby do.


Will running the car in it's present state leaving the aircon off cause problems in the short term???

Any advice welcome
Thanks
John

John,

You have a PM

[loupus666]

Hello chaps, half way through replacing mine & have had to drill out the two torx scews either side of the rad....could anyone tell me what they should look like & what they actually screw into as mine are now just swarf!
Thanks

[baxlin]

Can you be a bit more specific as to the location? eg on the slam panel? or visible only when the slam panel is off?

When I did mine the only ones I had trouble with were the air intake ones, which seem to be moulded into rubber, and two of the ones actually holding the fan motor to the fan shroud, all of which I replaced with S/S M6 set screws.

HTH

Malcolm

[loupus666]

All sorted now thanks Malcolm.....& have replaced all the corroded items with s/s as suggested.