75T Estate Electric Cooling Fan Keeps Coming On
 

Hi Guys....I have an intermittent problem with the electric cooling fan coming on. Over the course of 50 miles almost on a daily basis. The electric fan comes on and stays on. The engine is not over heating. I have to stop the car and turn the ignition off. This then cancels the fan motor and I can carry on until the next time it comes on.This can happen 2/3 times in the journey.

Couple of things I would like to ask...firstly there must be a sensor somewhere where is it and can it be replaced....Its getting so annoying can I disconnect it.there does not seem to be a fuse that controls it.

any suggestions

Thanks Bill

Is your car a manual or auto?

Manual

Thanks

Too little info me thinks. Do you check the car temperature with the OBD or just using the completely useless temperature gauge. Are you running your air-con and does it work correctly ? Need more for the gurus here to diagnose stuff, like maybe stuck thermostat, 2 thermos in line... myriad of things, but I'm just speaking from what I've read and done off of here.

Does your car have a resistor fitted on the fan at about the 2 o'clock position? If so, it has failed & you need to fit an uprated one. If not, then it may need a new motor, or, simply regassing. First though, aircon off, demist on, go to the front of the car & see if the fan is running.

Thanks where would I find the resistor

Bill

1.8T engine
 

Hello Bill,

Before we start talking about resistors, Martin has a good question:
Martin is referring to the instrument pack diagnostics which will show an accurate digital display of the actual coolant temperature. We need to know what that is showing when your fan starts running (and the air conditioning should be off).

Simon

75T Estate Electric cooling Fan keeps coming on.
 

Sorry Guys I dont have an OBD...But to elaborate on the problem the electric fan can come on at any time...However I have notice say on a motorway it seems to be ok manly because I suppose the air is cooling it down.and does not trigger a switch or something...What I dont understand when it comes on I stop the car and turn off the ignition then back on again it turns the fan off..it can stay off then for an hour or longer.

If the car was running hot when I stop and start again surely the fan would come on as soon as I start the engine but it does not...it seems to cancel out
until it comes on again. I can go many miles before it starts again. Then I have to go through the whole procedure again..

It seems that some sort of switch starts it off until I turn the engine of start again and its all right.....

how annoying is that.................Bill

All models have the OBD diagnostics, its accessed by using the button on the trip meter. See T-Cut's guide: https://the75andztclub.co.uk/forum/s...ad.php?t=55585

Yes you do Bill! The confusion arises because we’re not strictly talking about ‘On Board Diagnostics’ which requires interrogation by an external computer. It’s better to refer to it as the Instrument Pack Diagnostics but I’m the only one that does! Anyway, see the link which Steve has provided and it’s test number 7.0 which you need.

We understand the symptoms Bill. What we need now is for you to tell us the actual coolant temperature as you are driving and particularly when you hear the fan trigger. This is because your engine might be overheating even though you have been misled into believing that it isn’t by the useless temperature gauge. What should happen is that the fan starts running at 104 degrees and stops when the coolant temperature has fallen to 98 degrees.

You must have the air conditioning off during these tests because otherwise the fan will be triggered to cool the condenser, so ensure that the ‘Econ’ button is pressed.

So over to you Bill; some data please! :D

Simon