'04 LS V8 radiator fan

[fgilice]

I have a 04 LS V8 with 42k miles. Lately my cooling fan comes on too early and never goes off. It starts in about a minute after I start the engine even when its cold and the heating system is OFF. The coolant level is OK, temperatures are normal, heating and AC works properly.
Sending unit or relay switch?
Any thoughts? Where to look?
Thanks

 

[Quik LS]

is your AC on? Having the AC on automatically turns the fans on - so that the air is cooling the condenser even is the car it sitting.

 

[fgilice]

AC is off. Even when I turn the heating/AC system totally off the fan is still working.

 

[fgilice]

sorry I have to bump this subject up again but the problem is driving me crazy. In the middle of winter in Canada my cooling fan is working full blast all the time. It is not right.
Coolant level is ok, engine temperature is fine, heating works properly.
It goes on just before the engine reaches normal temp. and never goes off until I shut the engine off.
Give me something boys.
Thanks

 

[fgilice]

It was a thermostat. After replacing it everything is back to normal. The bottom, nedle looking part was stuck.
Wondering; even though the temp.gage never passed the normal/half way mark, is there a chance that I have overheated/damaged the engine?

 

[NYC LS8]

If it was stuck closed, possibly. If it was stuck open, no.

I'd like to think that Ford got wise after the first gen LS and put in stats that failed open.

 

[fgilice]

There is a fail safe built into these engines, I thought?
If you overheat it, half of the cylinders will shut down and eventually the whole engine will shut down.
That is what the manual says.
In my case nothing came even close to that.