Eric
222 posts
Joined: 21/06/2007 10:12:29
Location: Cranbrook United Kingdom (Excluding channel Islands)
Radiator fan always on
So both the minis have been running fine for a fortnight - it was about time for one of those little niggles.
The green mini mayfair (carb, early '90s) now has the radiator fan (next to the wing panel) permanently on, when the ignition is on, even if the engine isn't started and the radiator is cold.
I guess there is a thermostat somewhere that has shorted, or something? Anyone got any ideas what is wrong, or could point me in the right direction?
Cheers, Eric
PS OK a bit more research (good old Haynes) suggests it may be the 'Auxiliary cooling fan switch' - does that make sense? I'll test it tomorrow (if I get chance). I'm not sure if there is a relay in there which might be the fault? I couldn't find the switch listed in the shop - anyone better at finding things in there than I am?
Posted: Jul 25, 2007 07:26 PM
mark
397 posts
Joined: 18/08/2005 14:01:28
Location: Hitchin United Kingdom (Excluding channel Islands)
if it is the same as my 1990 cooper, its a sensor on the front of the thermostat housing. these sensors were about £50 as i recall, so i just left mine broken and disconnected.
part refernce on here is YWL10010
Posted: Jul 26, 2007 11:57 AM
Thanks for the rely - but gosh - that (http://www.minispares.com/Product.aspx?pid=33987) is expensive!
I was hoping it might be something like this (http://www.minispares.com/Product.aspx?pid=34882) which is a much better price. The car is a Mayfair, not a Cooper, and it is an L reg (93-94) so doesn't really fall under the pre-1992 category.
I've been away for the last fortnight, but I'll have a play with it this weekend. I hadn't really thought about just disconnecting it. Does that cause you overheating problems - or would you recommend it as a solution to a cheapskate?
Posted: Aug 14, 2007 10:41 AM
just disconnect it, the older minis never had an issue, although my 1990 cooper is a 1400 with a 2 core rad from minispares, when it was a standard cooper it was always fine.
Posted: Aug 14, 2007 03:39 PM
Thanks - I'll try that. At least it will stop my wife fretting and get her back on the road with the car.
While I'm there, I'll have a look at the switch and try to get an idea which one it is. I'm wondering if it is this (http://www.minispeed.co.uk/classic/index.cgi?task=showproduct&id=gvs104), which is much more the price I was thinking of (shame the site doesn't have a photo!) .
I understand that there is also a fan relay in there too - I'll check that as well, because if that is stuck on, I would think that would cause the same problem. Maybe a light tap on the relay to unstick it would help, or I might even be able to afford a replacement!
Thanks again, Eric
Posted: Aug 15, 2007 12:05 PM
taffy1967
1783 posts
Joined: 27/09/2006 18:58:07
Location: Rhondda-Cynon-Taff United Kingdom (Excluding channel Islands)
You're radiator will have the fan switch located at the lower front with 2 spade connectors attached to it.
Removing the grille will allow you to locate it easily and allow access if you want to remove the radiator too.
If you're radiator looks like it needs replacing, don't bother and just get it re-cored by a local radiator specialist and then they can fit a new fan switch and thermostat too.
Posted: Aug 15, 2007 03:27 PM
Just wondered - if I want to remove the switch, can I only do that by draining the radiator and so taking the car off the run? Or can I remove it without while leaving the radiator waterproof?
Posted: Aug 16, 2007 12:46 PM
OK, I found the relay and swapped it with another, and the fault was still there, so it wasn't that.
I took the grille off, found the switch and disconnected it. The fan stopped. I tested the switch, and the meter read less than 1ohm, so it had shorted. I took it out and caught (most of) the water. I tapped the switch on the ground and it read 3-4Mohm! I photographed it (it was this - http://www.minispares.com/Product.aspx?pid=33593) so I can buy a replacement and put it back. Works fine now!
Thanks for your help, Eric
Posted: Aug 18, 2007 06:46 PM
Nice one Eric.
Posted: Aug 18, 2007 06:59 PM
I felt so smug. A month and no problems. She has just called and said that the car was going well for the half hour journey into Maidstone, but when she had to sit in a queue for 10 minutes, steam started pouring out of the engine compartment. The fan didn't come on.
I'll order a new switch and learn a bit more humility.
Posted: Sep 11, 2007 10:44 AM
why dont you fit a secondary switch an parallel with the temp sensor, so it can be switched on by the driver in case of emergancy!
Posted: Sep 11, 2007 11:41 AM
Got the new switch yesterday (less than 24 hours for delivery!) and installed it post haste.
My wife says it is still overheating though! The fan belt is OK, and the engine side fan is rotating (although she did say that the auxiliary fan didn't kick in). How can something so simple be causing me such grief?!
Posted: Sep 13, 2007 01:09 PM
Sorry, I missed this reply before my last post. It's a good idea and getting pretty close - if I can't solve it soon, I'll do just that!
Thanks, Eric
Posted: Sep 13, 2007 01:24 PM
Checking it out over the weekend, I think I was just unlucky. I think the water system sprang a leak, and so the water was disappearing. I couldn't find it, so (against my better judgement) I got one of those funny pellet things that blocks leaks (a bit like Radweld), and the problem seems to have gone away now. I'll give it a week, then I'll drain it down, clear it out and refill with clear again, including antifreeze.
I just hope it doesn't bung up my in-car heater rad, like it did with my old Peugeot 405.
Posted: Sep 17, 2007 11:32 AM
Yes it'd be worth flushing that out because the bore on Mini heater matrix's is quite small and easy to block.
When you come to fill up with fresh coolant, just use good old fashioned Glycol based anti-freeze and avoid the fancy OAT pink stuff because that can have a similar effect on the heater matrix and isn't really suitable for cast iron cylinder heads either.
Posted: Sep 18, 2007 03:07 PM
john the miniman
21 posts
Joined: 23/02/2009 16:37:46
Location: Sheffield United Kingdom (Excluding channel Islands)
Radiator fan
Hi all - first posting here, so please be gentle with me!
I have a yr2000 Mini Cooper Sport Classic, and the radiator fan seems to have gained a mind of its own. It's not been driven for a full 24 hours, and suddenly the radiator fan comes to life. It keeps running for a few minutes then stops, only to start up again a couple of minutes later.
Anyone have any ideas how I can get rid of the poltergeist that has clearly taken over?
Many thanks John
Posted: Feb 23, 2009 04:45 PM
Dennis
6 posts
Joined: 07/05/2007 22:17:28
Location: Paisley United Kingdom (Excluding channel Islands)
Radiator fan not coming on
As the title says, my fan won't kick in so I'm overheating sometimes.
I've changed the temperature sensor, the thermostat, drained flushed and refilled coolant, no air pockets, no leaks and the fan comes on when I put 12v through it.
In the meantime, a friend wired a switch up for me to put it on manually, but I'd prefer to have it working properly...
Any ideas anyone?
Posted: Sep 01, 2010 02:51 PM
Tim
1849 posts
Joined: 18/10/2004 09:40:59
Location: Bournemouth United Kingdom (Excluding channel Islands)
I would fit one of those adjustable Kenlowe thermostats with the relay built-in.
Posted: Sep 01, 2010 04:25 PM
John
1948 posts
Joined: 28/05/2006 16:49:46
Location: cambridge United Kingdom (Excluding channel Islands)
Fitting an electric fan in a pre-1990 mini!!
yes it would, improved radiator is like a larger heat sink, it does help in traffic, if u use a large enouth radiator u dont need a fan at all. may people fit frount mounted radiators of larger capasity to thr frount of minis without a fan at all, and they still dont overheat when stationary. the fans added in the wings do not help very much as they are the sucking type and are too far away from the radiator to have much effect. on my 1275 iv never had the fan kick in once as its thermostate controled.
the standard fan is still spinning 16 times a second at idle, still moves enouth air.
my plan for my 1275 cooling is to do away with the mecanical fan. cut the inner wing so i can mount a electric fan close to the rad. then have an auxilary radiator from other end of the head (heater element). with a 4core rad at other end. will aid power as the fan uses. the electric fan will be thermostate controled so engine will warm up quicker also. it will also be less noicy as fan wont be on most the time.
Posted: Jun 14, 2007 01:38 PM