Cooling Fan Relay Box Cover

[Steve2016]

Hello. The cooling fan on my R75 Diesel Estate 2004 is staying on. From my research it seems like the relay is stuck on, so... I have removed the bumper and the horn and I can see what I think is the relay cover but I can't work out how it comes off.

Does it just pull straight off forwards or is there some other jiggery pokery required?

Many Thanks,
Steve

[Arctic]

Hi Steve.
When you say it's staying on do you mean after you have turned the ignition off, or just when the car is running?

Also have you looked to see if you have a silver resistor at about 2 Oclock, if so this could be the fault, and needs changing for a gold one.
1

2


To look at the relay's you would need to remove the alloy crash bar, four bolts either side and one nut either side, always best to remove the slam panel in my opinion, but you could try below.
3

4

Once the crash bar is off you can then remove the cooler assembly pipe for the power steering, tow 10mm bolts, first crack the 8mm bolts holding the temp sensor, and remove.
5

Then the two 10mm bolts for the cooler pipe.
6

7

Lay the pipe down on the ground.


Then undo and remove the four 8mm bolts hold the fan to the car, this may just about give you room to pp out the control box it will be tight.
8

9

Now the two holding the fan to the intercooler.
10

11

Even after all this work it will be hard to remove the relays, and you could damage the PCB which could also be the problem.

So it would be best to get the fan on a bench after a few tests have been completed, that means removing the slam panel with light attached.
12

[SD1too]

Originally Posted by Steve2016

The cooling fan on my R75 Diesel Estate 2004 is staying on. From my research it seems like the relay is stuck on ...

The relays are actually very reliable Steve but a favourite diagnosis since they're easily replaceable. Before going any further we need a bit more information as requested by Arctic. Does the fan never stop running so that you have to disconnect the battery to stop it? Or does it run on for a short time once the engine has stopped and the ignition key has been removed? Please let us know.

Simon

[vitesse]

A very recent Danish post of the fan always on turned out to be a break in the sensor wiring (very active mouse) causing the EMU to activate the fan in emergency mode as it was not receiving an active signal from the sensor.

Regards

[Steve2016]

Thanks all for getting back to me so soon.

The fan runs continuously after turning off and removing the key. I had to remove the big fuse in the fusebox near the battery to stop it.

It has a silver resistor just behind the fan.

[Arctic]

[QUOTE]

Originally Posted by Steve2016

Thanks all for getting back to me so soon.

The fan runs continuously after turning off and removing the key. I had to remove the big fuse in the fusebox near the battery to stop it.

It has a silver resistor just behind the fan.[/QUOTE

]

Hi Steve.
It could be the silver resistor is shorting, if they fail the fan would not run most of the times, then it could be the PCB in the control box, i'm afraid it's a fan off the car job to investigate, if you could hold out until our next Nano meet in September we could help you take a look at it at the meet.

If not then it's bumper off, slam panel off with crash bar and lights attached, then fan off to give it a good visual look over for any wiring chaffing etc.

[vitesse]

Steve, on the 2sp resistor fans I've tested I believe that when the resistor burns out it leaves the fan with only one speed (high?), or have the owners just been lucky? I should perhaps mention I've only ever tested a diesel once, all others have been petrol models.

Question for the OP. Does the temperature gauge register at all?

Keep well,

Mike

[Arctic]

Originally Posted by vitesse

or have the owners just been lucky? I should perhaps mention I've only ever tested a diesel once, all others have been petrol models.

Question for the OP. Does the temperature gauge register at all?

Keep well,

Mike

Hi Mike.
yes you are correct i should have been more clear when i said (if they fail the fan would not run most of the times,) in that it would not run in low speed.

If it's running al the time something like a short or PCB trouble could well be the problem, that's why i suggest to remove the fan from the car completely to investigate relays and al wires.

[Steve2016]

Originally Posted by vitesse

Steve, on the 2sp resistor fans I've tested I believe that when the resistor burns out it leaves the fan with only one speed (high?), or have the owners just been lucky? I should perhaps mention I've only ever tested a diesel once, all others have been petrol models.

Question for the OP. Does the temperature gauge register at all?

Keep well,

Mike

Hi Mike. The temperature gauge appears to work in that it still points to a tadge below the 9 o'clock position, like it always has done.

[vitesse]

Originally Posted by Steve2016

Hi Mike. The temperature gauge appears to work in that it still points to a tadge below the 9 o'clock position, like it always has done.

OK thanks Steve, I just wanted to rule out a possible problem with the temp. sensor. Looks like you are going digging, or take Arctic up on his kind offer of help at the Nano. I believe he and Stocktake hold the world record of fan repair and even though I've done 13 or 14 repairs, my repair time comes nowhere near theirs.

Keep well

Mike