My radiator fan has stopped working after only being in since March so I'm assuming it's burnt it'self out because the 40amp fuse looks fine. Now are radiator fans supposed to be on constantly or are they meant to kick in and out as required by the cooling system? Mine was always on and never turned it'self off (apart from when the engine was off obviously) so could this be the reason it's died so quickly? What could the underlying cause of it always being on be if it's not supposed to be on always?

wow something is wrong, fan only ment to be on when needed, there is a sending unit at the bottom of a radiator which sends data to the ecu to swich the fan on when it gets too hot, but it will also turn on when the aircon is running, so unless you had your aircon on at all times i suspect it was the sending unit that was malfunctioning thus making you fan to work at all times.

Thanks haven't had the air con going at all over winter so it's definately not that. I guess that a radiator replacement is on order then or can that sending unit be replaced on it's own?

Try to download the factory workshop manual and read the chapter on cooling system, for description and troubleshooting info. There are older threads in here that have good info about diagnosis and repair of cooling fan issues as well.

If the fans run constantly without air-con switched on, that's definitely not correct operation. Could look at relays (checking if there are seperate relays for normal vs air-con operation of the fans), look at the coolant temp sensor for the fans (this is different to the coolant guage sensor). Are you new fans actually dead - rig them temporarily direct to battery to see if they will run..... and so on. All the common and easy causes are detailed in the workshop manuals, then proceeding to more difficult or less likely causes.

If you have a TE or TF, just use the TH manual, which will be practically identical for the cooling system.

Ok I found out by doing a test in another thread that the fan is actually ok, it's that sensor. I can't find the sensor in the workshop manual though so where abouts exactly is it?

On a 2nd gen it is at the bottom of the radiator on the driver's side. Pull the plug off and with the ignition on and engine off short the two connections in the plug. The fans should run if the circuit is ok. Pull the sensor out. Cold it should be open circuit with a multimeter, drop it in hot water for a few minutes and it should go closed circuit. replace as needed.

If all is working properly the fans will only cut in for 5 to 10 seconds with the engine hot aftert a drive, and the car stationary and idling for several minutes. The temp guage should be rock steady during this cycling.

Activating the aircon should make both fans run no matter what the engine temp is.

Ok so this morning the fan seems to be working again after I hadn't done anything to it. It runs on low speed now but won't go higher and it still decided to overheat once at lights during a long drive this morning.

Could the problem now more likely be the thermostat?

Hey mate, i have a similar problem myself... the damn thing basically wont run on when it needs to, so engine will start heating up now & then on the traffic lights, i changed thermostat, did nothing. Basically when it fails to swith on when needed, i.e your temp gauge goes past the middle, just swich on the air con for like 5 seoncds this seems to trigger fan to start working & it will swith off when engine cools down. I have been told to run a diagnostic on the ECU to see if the temp sending unit is stuffed, but the charge like $80 to just get the reading of the ECU, so for the moment ill just stick to hitting aircon button when it fails to turn on.

Cheers

Guys, if you are wondering where your posts went, I have deleted them as this was an issue back in 2009 and posting up a link to fault codes some 2 and a half years later, while a nice thought, is pretty much useless to the person who would hopefully have resolved this long ago