radiator fan not worked in 7+ years by Ed3



Ed3
When I was at the nano last year it was noted by those there that my radiator fan did not kick in.

I bought the car in November 2017 and have never heard the fan. But I mainly do long trips often on motorways, as opposed to being in a traffic jam on a hot summers day.

In 2017 the car was over cooling and so I fitted an inline top hose thermostat MOD and since then the temperature soon warms to a perfect 9'o clock but never higher.

So I was thinking may be no urgency but wondering what to do as a fix eventually?

Posted 05 Apr 2025, 19:13 #1 

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Duncan
From your description it sounds like you have a CDTI. They tend to run cool so usually not a problem TBF. However, if you use the air conditioning, it can cause spikes in AC pressure which are not good for the system.

Regarding the fix, it depends on what the problem is. Did I test it on the T4 (Testbook version 4.Computer Diagnostic System)? If it is a CDTI then it could have two different fans depending on the age. Earlier ones had a three speed fan, and the brushes wear out. The fix is usually a replacement fan motor, though the brushes can be replaced. Later cars had a two speed fan with a resistor that fails, and its a fairly easy resistor replacement. There are other failures, but those are by far the most common failures and fixes.

Fan diagnosis and fixes are smoething we at the Nanos are quite experienced in.
Image

Posted 05 Apr 2025, 19:26 #2 


Ed3
Sounds like something to chat about at a Nano.

There as no T4 on the days I was at the Nano

Posted 05 Apr 2025, 19:33 #3 

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Arctic
(Trader)
Ed3 wrote:Sounds like something to chat about at a Nano.

There as no T4 on the days I was at the Nano


Hi Ed.
If i remember rightly we did the demist test and the fan was not running, but remembering if you had the fore wire 3 speed fan or the two speed with silver resistor eludes me but you can check your self by looking through the front grill at about 2oclock see if you can spot a silver resistor.

If yes we can sort that out at the next Nano meet if so wished to come, if it turns out you have the four wire 3 speed fan we can also sort that out, do let us know so I/we can then help you get it sorted out.

As far as the 9 oclock on the dash for your temperature that stays the same even if the engine was 75c or 90c you can test the true temp by using the OBC (On Board Computer) press 19 then 7 video below.
https://youtu.be/OcB5WLEPdL8?si=5T-BUZpwNScEYIMj

Arctic
Pearl Firefrost
ARCTIC

Posted 06 Apr 2025, 01:11 #4 


Ed3
Thanks Arctic, I just checked and looks like a silver at about 3 to 4'o clock. The car is a CDTi saloon 06 plate from the last month of production and stored for a year of so by a Dealer. I see if I can make the Nano.

Posted 06 Apr 2025, 02:04 #5 

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Arctic
(Trader)
Ed3 wrote:Thanks Arctic, I just checked and looks like a silver at about 3 to 4'o clock. The car is a CDTi saloon 06 plate from the last month of production and stored for a year of so by a Dealer. I see if I can make the Nano.


Hi Ed.
Quite an easy fix then about 45mins bumper off job, it can be done at the Nano but if you can not make it drop me a PM i have the gold resistors already made up, and I'm sure you could tackle the job your self like other jobs you have done on the car :thumbsup:

You have completed the first job doing the check that you have a silver resistor in place on your R75/MGZT doing this by looking through the front grill at about 2.0 Oclock Fig1

Image1

Once you have established you have a two wire 2 speed fan with silver resistor remove the front bumper Fig 2
Image2

Now you have the front bumper removed unplug the fan from the car loom as the fan is permanent live on a diesel Fig 3
Image3

Your nest step is to remove the crash bar 4 bolts and 1 nut each side 13mm Fig 4/5/6
Image4

Image5

Image6

Once you have all bolts and nuts removed take off the crash bar Fig 7
Image7

Lie the crash bar to one side out of the way Fig 8
Image8

The main reason for removing the crash bar is that is will give you more access to remove the silver resistor and fit the gold one, working through the largest gap in the fan blade Fig 9
Image9

Remove the two screws holding the fixing plate to the fan for the silver resistor Fig10
Image10

Image10a

With the two screws removed pull the silver resistor through the fan blade Fig 11
Image11

Now you have the silver resistor through the fan blade cut the black wire as close to the resistor end as you can, giving your self a good length of wire Fig 12/13
Image12

Image13

You now need to strip back the wire ready for soldering or crimping the gold resistor to Fig 14
Image14

Hopefully you have wired the gold resistor already with a small tail to aid the fitting to the fan black wire, or you have purchased a gold resistor already fitted with the tail, you need to push these together weather you are soldering or crimping. Fig 15
Image15

The gold resistor I use at the meets or on members cars already have the wire tail fitted before and crimped so all I have to do is crimp the joint to the fan wire Fig 16
Image16

Make sure your crimping is good and tight and remembering to add a length of heat shrink onto the wire before crimping Fig 17

Once you are satisfied with your crimp or soldering heat shrink the joint Fig18
18

Repeat this procedure for the other wire on the fan again making sure heat shrink is added before you crimp or solder Fig 19
19

Feed the gold resistor and wiring back through the fan blade fit the resistor to the fan using the screws you removed earlier, and cable tie the wiring to the fan supports to stop the wire from touching the condenser and fowling the fan blades when it is running. Fig 20
Image20

Now you need to test the fan refit the loom plugs in the wheel arch, if you are working on a diesel car ignition to II with all A/C off press the demist button, on a petrol car you will need the engine running, the fan should run continually switch off the demist button and retest a few times before refitting the crash bar and bumper, you have now completed fitting a gold resistor.
Cheers Arctic
Pearl Firefrost
ARCTIC

Posted 06 Apr 2025, 07:51 #6 


Ed3
Thanks, that looks exactly like what I have. Though I can see the bottom black wire a bit more. I will PM. Thanks

Posted 06 Apr 2025, 12:05 #7 


Ed3
PM sent but I am not sure if messages leave the outbox

Posted 06 Apr 2025, 16:16 #8 

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Duncan
Ed3 wrote:PM sent but I am not sure if messages leave the outbox


They stay in the outbox until the recipient reads them, so don't worry about that.
Image

Posted 06 Apr 2025, 17:50 #9 

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Arctic
(Trader)
Ed3 wrote:PM sent but I am not sure if messages leave the outbox


Hi Ed.
PM received and read also replied to, you can come to meet or i can post one out to you, let me know your choice.
Pearl Firefrost
ARCTIC

Posted 06 Apr 2025, 23:37 #10 


Ed3
Thanks Arctic. Regards the meet. I assume the meets are now only one day. Does anyone know if the owners of the venue are still keen on tents? If so I could drive on Friday and be there ready for Saturday?

Posted Yesterday, 10:21 #11 

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Arctic
(Trader)
Ed3 wrote:Thanks Arctic. Regards the meet. I assume the meets are now only one day. Does anyone know if the owners of the venue are still keen on tents? If so I could drive on Friday and be there ready for Saturday?


I'm sure Rob could find out for us.
Pearl Firefrost
ARCTIC

Posted Today, 02:22 #12 


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