cooling fan running constant

[Griff72]

Hi all I have a problem with the cooling fan on my Signum 1.9 cdti (150) 56 plate.

When you switch the engine off the cooling fan is kicking in i've never had this before but was assuming it was the warm weather we are having, the problem is though the fan isn't switching off it was running an hour or more earlier without the engine running, I had to remove the fuse to stop it.

Not sure if its the rad cooling fan or the air con fan but its the right hand one as your looking at the front of the car with your head in the bonnet.

Any ideas or anyone had a similar problem I don't fancy a trip to the dealers!!

Thanks for any forth coming info!!!
Ste

[Das]

I take it that it is running with the engine running too? Check the electrical plug has not come off the thermostat housing. Sure its a fail safe, in case it comes off, the fans run to prevent the engine over heating.

[Griff72]

No when you switch the engine on the fan cuts out, knock the engine off and after a second or two the fan kicks in again and runs constant.
Do you know if its the rad cooling fan or the air con fan??

Cheers for reply.
Ste.

[Dannyboy444]

Have you got water in rad?
Dan

[Griff72]

Yes checked that too plenty coolant in there!!

[Griff72]

Could it possibly be the temp. sensor telling lies??

[Z80]

Could be.

Could also be a problem with the coolant circuit, or the pump, or the pump not spinning correctly.

My crankshaft pulley went loose, then broke, so the water pump wasn't driven anymore (or insufficiently), so of course, the fans started to run in an attempt to cool the engine down... Until they emptied the battery, that wasn't charged anymore BTW, as the same belt didn't drive the alternator anymore either.

You should check on that anyway, considered how much hassle this can bring.

[Griff72]

Ok thanks for reply don't think its along those lines (although I will check) because I have had no eratic temp changes on the dash gauge and the fan is running constant whether the engine is hot or cold.

I put the fuse back in this morning when the engine was obviously stone cold and the fan kicked in straight away. Just had the temp. sensor tested by a spark at work and he seems to think that is behaving so looks like I'm gonna have to run into the local auto elec's!!!!!

Out of interest does anyone know why there is 2 fans on the rad. the car does have air con and the fan that is running constant is the right hand fan loooking at the front of the car.

Any info much appreciated!!
Ste

[m8internet]

The radiator cooling fan switch has failed and needs to be replaced

[Griff72]

Ok mate thanks for that have you had the same problem? where is it located, is it a main dealer part?

Thanks for reply.
Ste