Rover 75 Diesel - Cooling Fan Box Unknown loose cable
 

Hi guys, just came across an unknown loose cable wire (circled in red) nearby the Siemens fan relay unit box whilst cleaning a 75 Diesel that I just got. Could it be coming from the white plug connector? (also circled in red) As I noted that the white plug connected is only connected at one of the two terminals.

Any idea where should it be reconnected?

https://ibb.co/jyPK2hG
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https://ibb.co/jyPK2hG

https://ibb.co/KGwRMgR

https://ibb.co/HBcFsqp

Many thanks in advance all.

Warmest regards
Zick

HI Zickleer.
Your diesel fan looks to have been butchered for some reason can you open the black control box and post up photo's, also have you tested the fan by turning the ignition to II making sure all the A/C is switched off then press the demist button if not please do so and report back to us please.

The red wire coming from the black control box splits into two black wires one of the wires should be connected to a silver/gold resistor, so should the grey wire coming from the control box, it seems yours as been disconnected and the grey wire goes to the chassis leg by way of some sort of earth point?

https://i.imgur.com/cyQgx72l.jpg1

How your wiring looks coming from your black control box.
https://i.imgur.com/TeUf1xol.jpg1

https://i.imgur.com/hSLH3dnl.jpg2

https://i.imgur.com/xBgjmawl.jpg3

Thank you so much for the speedy reply Arctic, here is the photo of the opened fan relay box.

https://ibb.co/ySkd16M

Additionally the fan has always spin whenever the ignition key is at "ON" position all the way thru driving and only stops after about 10 seconds the engine is switched off. I have checked all 3 relays for continuity and resistance and 3 worked fine. I have upgraded to the gold resistor but nothing seemed to changed.

Will report back on the demist test as it's 8pm and super dark right now where I am at.

Thanks once more Guru Arctic 👍🙏

As suspected the gold resistor is missing from you photo, and it looks like its been made permanent live.

Do you have a photo of how the wiring is now if you have added a gold resistor ?
your photo of your control box
https://i.imgur.com/XIbBa9Nl.jpg4

You are right Arctic, I have traced the red wire from the box and it splits into 2 wire whereby 1 goes to the gold resistor in a loop and exits the resistor as the grey wire and gets connected back to the fan relay box. The other 1 split wire (front the red wire) is the butchered one. Should I ground the butchered cable? Or does this butchered wire goes elsewhere? Not very sure if I have accidentally ripped it from the grounded position as I removed the spam panel 😅


Thanks once more Arctic 🙏, I felt much matured during the ownership of this Rover from my prior Hyundai Sonata NF 😊

https://ibb.co/ZdtQsMn
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I am really sorry to take your Sunday rest time, Arctic.

Here's the photos, I just snipped off the old resistor and then added some short wires to the gold resistor as the existing wire is too short(after being snipped off) and thus making it bent at an awkward angle. The addition aly short wires(in blue) prevented the awkward angle bent.

Should I ground the butchered cable? Or does it goes to 1 of the white socket's 2 terminals? Clueless at this point 😅

I think my next step to solve the forever spinning fan (never stops throughout whole journey until about 5-10 seconds after engine is switched off) would be diagnosing the coolant temperature sensor.

Thanks Arctic

Apologies Steve for jumping in but this is a fascinating puzzle!

The thick red wire exiting the control box was earthed at the open chassis box section but, as you say, became detached during dismantling. This earthed wire by-passed the control box relays.

Zickleer, please confirm to which colour wires you have connected the resistor and where those wires go. I can't tell from the photographs.

Simon

That's a relief 😌

Thanks Simon, I tried to put on econ mode, but there is no effect, the fan still keeps spinning.

The red wire exiting the relay box is spliced into 2 wires, whereby 1 goes to the resistor and loops back onto the relay box, whereas the other 1 supposed got detached from being grounded. Can I know the reason the prior owner grounded the wire to bypass the relay? As Even being detached from grounded, the fan still spins continously like before.

Any idea which is the right connections? As I'm not sure if the resistor connections are even right in the first place 😅

Any other options that I can follow to resolve the continuous fan spin? Would it be a case of a failed coolant temperature sensor?

Yes, I know the right connections. I have your PWM2 circuit in front of me, drawn some time ago with the generous help of Arctic.

I need to know how you've connected the resistor. Can you tell me the colour of the wires and where they go. Then we can begin to form a picture of what has been done. At the moment I suspect that the fan motor has somehow been wired to run permanently because switching to 'Econ' mode on a diesel should silence it. So forget about the temperature sender for now.

Please reply asap with those wire colours.

Simon

Apologies for the confusion Simon, I just replaced the silver resistor which was connected from the relay box's red wire (which was spliced into 2, whereby 1 goes to the resistor whereas the other 1 was left detached). The replaced Gold resistor then continues its connection in a grey wire looped back into the relay.

The resistor is not in anyway connected to the fan motor. It is just connected on a loop from the relay box and then back into the relay box. Does the resistor need to be connected to the fan motor?

Apologies for turning Sunday into a manic one 😅