Hi all,

Title says it all really........ What should I check to see what is causing the radiator fan not to kick in?

Thanks in advance

most likely fuse under steering wheel. after that, check the connections on the thermostat. if not then might be ur ecu as the fan is ecu controlled or the fan is burnt out. most likely one of the first 2.. hopefully!

 

most likely fuse as already mentioned it could be the thermostat as well but first make sure that everything is ok with the fuses

 

what a day its been!

Ok we have checked the following:

*Inspected the fuses, all look visually perfect.
*Removed the fan and tested it by connecting it to a battery jumper kit, the fan started up fine.
*Changed the brown coolant fan thermostatic switch for a brand new one.

Still the fan fails to kick in. Is the only other possibility the ECU?

Incidently, I read somewhere that unplugging the brown thermostatic switch, while the ignition is switched on should start the fan automatically. Is this correct? And does the fact that mine doesnt automatically start another bad sign pointing towards ECU probs?

Cheers

 

Not sure about that disconnecting the fan = auto start thing - but maybe the engine temp isn't getting high enough to warrant the fan coming on?

To be honest, I don't know if mine works either - never heard it come on, but then my engine temp has never ever gone above halfway (except when my headgasket went)

 

I have let the temp guage creep up to 3 quarters with a lot of finger crossing but dont want to let it get any hotter.


From what I gather the rad fan should kick in as soon as the guage starts creeping over 1/2 way - mines going alot further than that.

 

what a day its been!

Ok we have checked the following:

*Inspected the fuses, all look visually perfect.
*Removed the fan and tested it by connecting it to a battery jumper kit, the fan started up fine.
*Changed the brown coolant fan thermostatic switch for a brand new one.

Still the fan fails to kick in. Is the only other possibility the ECU?

Incidently, I read somewhere that unplugging the brown thermostatic switch, while the ignition is switched on should start the fan automatically. Is this correct? And does the fact that mine doesnt automatically start another bad sign pointing towards ECU probs?

Cheers

the fan has two scales slow one and fast one
when you disconnect the brown thermostatic switch the cooling fan and air/con fan start operating at scale 2 (fast one)
i instist you go over the fuses again because i had the same problem once i checked the fuses..seemed ok..took it at the garage..and finally it was fuse problem which i hadn't inspected carefully!
do you have a/c? if yes when you switch it on do coolant fan and a/c fan operate at scale 1 (slow one)?

 

interior main fuse box check fuses 15,19
engine compartment fusebox check fuses 4,6

 

dont have ac - I will just have to try changing the fuses to see what happens.

Incidently, when I short out the brown temperature sensor to try and get the fan working, although the fan doesnt work, an 'electrical' noise comes from somewhere near the fuel injector.............what noise is this?

 

sorry can't think of sth about that noise..

 

by the way..don't be disappointed thinking of damaged ecu..
next to the engine compartment fuse box, there is one yellow/black relay which controls fan's scale one and two..there could be a malfunction there!

 

take a look at this.. it may be helpful..

the SU wire "comes" from the ecu and "tells" cooling fan relay whether to function or not

 

you are quite right, the fan should come on when the wire is pulled from that casted elbow no matter how cool/hot the engine. That noise you hear is normal.

 

thats good, but out of general interest........what is that noise?

 

Is it possible to by pass the coolant fan relay?

 

u can connect the PU wire with the UP one and the fan will always be on..
or you may use a switch between PU and UP and activate it wherever you want..
ONLY TEMPORARY SOLUTION

 

Bodging it as described will work but it isn't an ideal way out.

What happens that one time you forget to fire the fan up when in traffic :spanner:

 

i just suggested what the available options are..in no way i would recommend such a solution for permant use..

 

Cool - didn't mean to come across in such a way.......

Cheers for the info :spanner:

 

That do not have letters on there, they have numbers-

30, 85, 86, 87

???

 

any time mate
mgreen seeing your other post you have to take into account that:
by bypassing the relay the fan may work. this means that fuse 4 is ok and power management functions fine..
however you won't have figure out the solution since it could be either the relay or the ecu because by bypassing the relay you bypass the ecu command as well
i think if u earthed the su one (havind disconnected it from ecu) and directing the earth to relay could show you whether the relay operates or not..but i m not sure whether this is safe to attempt

 

That do not have letters on there, they have numbers-

30, 85, 86, 87

???

? don't get your point..

 

That's standard relay pinout numbering....