15 replies to this topic

[mykweb]

here is a weird one.

Since yesterdays rooting around and swapping over my temp sensors as I was getting misreadings. I have not got a new issue which I can't fathom

When the engine is stone cold... the fan comes on when the engine starts

I had a root about on the internet and previosu fixes have been check the wiring and also replace the temp sensor in the stat housing.

I sat this morning and fully removed the engine harness, and stripped it all back, and followed the two wires, Pink - Green and Pink - Black from the temp sensor plug to teh Black ECU plug. I ever found one split, missjoin, or fault in the loom.

Also I replaced the temp sensor with a new one I had bought last week... and still the bloody fan stays on.

Any idea?

I am ready to stick a seperate switch on it and use it manually... but not a good idea

Mike

[elvisthepizzaman]

Just because you visually followed the wiring from the connector to the ecu plug does not mean that there isnt a break in the wire. The wires that get vibrated a lot can/will fail inside the insulation so the only way to tell if you have a problem is to hook up a multimeter and check resistance. a better way would be to use a test light and a battery to see if there are fluctuations in current flow while you bend and twist the harness. The problem with taking the entire harness out of the engine bay is that you have disrupted the natural layout of the harness and if there was a slight fracture in the wiring it might have reconnected itself. If you test the resistance and it comes up with zero then you need to put it back into the engine bay and retest it. Since the harness has been opened up, you could run two new wires along the existing one but leave them unattached so that when you retest the resistance and find that there is a break you can simply splice in the new wire.

[200dl]

Read this thread: http://www.theminifo...howtopic=133108

[Sprocket]

Is the oil temp gauge reading OK?

I say this as there is a theory that the oil temp sensor also feeds into the ECU even though the Rover wiring diagram does not show it as such, Perhaps an Omission, I do not know, there is no one that can really say one way or the other unless they strip back a loom and follow the wires.

I have read some where that when the oil temp sensor reads high the fan comes on to cool the engine down and thus bring down the oil temp, but, there is no one that can confirm this.

Just another possability

[mykweb]

Ok I went to the motor factors today and Bought a new temp sensor.. plugged it in and.....same bloody issue.

I had previously disconnected the ecu multi plug, and stuck the positive side of a 12 volt cat battery on the pink/black & pink/green and then measured it at the brown plug end and stuck the multi meter between the battery negative and the brown connector.

I was getting a reading of 10.51, this is the same reading I was getting when I checked the battery on its own.

So I think I rule out a wiring short or misconnection. I also Jiggled the loom about and the voltage reading never chnaged.

I also ran the multimeter in Ohm mode and there was No resistance

So I am now at a total loss I now have 3 temp sensors bought over the last few weeks and they all do the same

Anyone got any other suggestions. Apart from keep taking the fuse out LOL

[minimat]

I thought i read about a problem with the sensor wiring being too short a and chafing through causing the fan to run constantly.
I believe there was a official rover part to cure this comprising off a longer wiring loom to this sensor?

[mykweb]

I thought i read about a problem with the sensor wiring being too short a and chafing through causing the fan to run constantly.
I believe there was a official rover part to cure this comprising off a longer wiring loom to this sensor?

done that already

Mike

[datsun100a]

Did you check the fan relay?

[mykweb]

you mean check to see if its working or if its faulty.

surely if its faulty it would not work at all.....right?

Mike

[mini.rich]

you mean check to see if its working or if its faulty.

surely if its faulty it would not work at all.....right?

Mike

That depends whats wrong with it, if your control side (ie, the coil) is damaged then it will not work. If however the load side is at fault it could potentially stay on, if the contacts have welded/burnt themselves together.

Does the fan come on still if the sender is disconnected?

Failing that you may be getting a constant signal from the ECU, that is if it is controlled from the ECU-but i dont know without looking at a diagram.

[mykweb]

went out tonight and swapped the relay over.. still made no difference.

as for disconnecting the plug, yes the fan will say on as a fail safe. But then the fan stays on even if its connected

Its funny I just had a thought. This kinda stems from when I replaced the stat. Might pop the old one back in

Mike

[Sprocket]

Does the temp gauge work?

Replace the oil temp sensor, then have the car looked at with a diagnostic and a person who actualy knows how to use it

[mykweb]

both oil temp and water temp gauge works.

Yeah think I am going to have to get the diagnostics machine out and see what the thing is saying.

Mike

[taffy1967]

This is the usual cause and Mini Spares have the required parts: -

Click Me

[Bochen]

So Mykweb, did you solve this problem? I ve got the same thing going on with my Mini and I am looking for any tips that might be helpful. I also changed the temp sensor for a new one, checked the wiring but still - the fan keeps going all the time. However there is a difference between my case and yours - my oil temp gauge seems to be dead. Please, let us know, if you find the solution.