Thermo fan runs all the time

[Nathan 2005 D22]

Hi
I have a 2005 D22 3.0L Diesel. Recently I have noticed the thermo fan running as soon as I switch the reds on, It did it a for a while a few months ago and it fixed itself? Now its back. Its not temperature related as its winter now and cold in the mornings.
Has this happened to anyone before and is it as simple as replacing a relay maybe?

 

[Dave]

Check the ECM's temp sensor on the engine.

Its a fail safe the ECM has.

The air con on ?

 

[Nathan 2005 D22]

Check the ECM's temp sensor on the engine.

Its a fail safe the ECM has.

The air con on ?

Air con is off. But a ECM failing sounds very probable I'll get it looked at... I'll be sure to post back when I know what it is
Thanks.

 

[Dave]

How'd you go ?

 

[Flynndog]

I'm gonna bump this as I recently noticed mine doing the same. As soon as the vehicle starts, the fan is on, always. Unsure how long this has been the case, I only noticed, maybe three months ago. Haven't really investigated as there is a lot more going on with the nav.

Would it be at all related to all my other issues perhaps if it was my ECU (Battery light intermittent, air con blowing a fuse and on one occasion couldn't stop the car, then it wouldn't start either).

 

[nathand22]

I

Would it be at all related to all my other issues perhaps if it was my ECU (Battery light intermittent, air con blowing a fuse and on one occasion couldn't stop the car, then it wouldn't start either).

It does sound like you need a good auto electrician mate.

 

[Flynndog]

More time would be good

I have a new air con sourced for $98. OEM unit, but now I am wondering if it is that; I had it looked at when we got to Perth and was told it was OK. Bloke re-gassed it, went fine for about 2 hours and blew a fuse again. Never took it back, but it's coming up on my list again.

So with an ECU, is that a straight swap out? Are they expensive?

 

[Dave]

Check the coolent temp sensor. ECU's rarely @#$% up, so I'd leave that till last.

 

[Flynndog]

Cheers Dave, on the list #243. Should be done sometime around September 2015

 

[Flynndog]

By coolant temp sensor you mean thermostat? I can't find a reference to it (coolant temp sens) in the manual. Also states that the ECM controls the fan function as you said before.

So if I have a faulty water pump, that could contribute to the fan issue?

Aircon is off (because its blown it's fuse again).

I have determined that my coolant is leaking around the water pump area so that needs to come off at a minimum.

Guidance wise ones?

 

[nathand22]

there must be a temp sensor, how else does your ecu gather its info for your temp gauge to work.
Just the same as there is an oil pressure sender unit there has to be a water temp sender unit.
Have you checked all the wires coming off both units, is there a common wire or do both the a/c and the fan use the same set of wires to draw their power??
or do they have a common earth??

 

[Flynndog]

Found it (Supplement VI 1st Revision Volume1 - EC-822). ZD30 engine