After reading a lot about how wrong it is to connect radiator fan directly, I decided to pay close attention to mine.
Unfortunately, it's been altered and the fan runs non-stop (don't know when, but probably when they convinced me to switch to double cell radiator).

Went to have it fitted the right way. First, after fixing back the 'regulator' on the body of the fan's casing, the fan wouldn't run except the ac is on: comes on as soon as the ac is running(and won't stop for throughout the 10mins of this experiment) and goes off as soon as the ac is off.
The mechanic's explanation is that the thermostat on the engine has been removed(not sure if that's true), which should be communicating with the fan 'regulator'.
Abeg, what could be responsible for this and how do I fix it.

NB: The car runs fine, except that the temperature guage never reaches the mid-point once the ac is not in use. I just want am d way oyibo mekam.

Gazzuzz, siena, ikenna come ooo

Ur mechanic might be right. The thermostat must have been removed which makes the fan run non stop once ur ac is turned on. The way the cooling system works, when thermostat is open, it allows water from the radiator flow through the engine, which signals the engine coolant sensor and activates the cooling fans. Without thermostat water will be flowing in and out non stop, hence the fans would be working non stop. The fans stop working when the thermostat is closed.

abatically:
Ur mechanic might be right. The thermostat must have been removed which makes the fan run non stop once ur ac is turned on. The way the cooling system works, when thermostat is open, it allows water from the radiator flow through the engine, which signals the engine coolant sensor and activates the cooling fans. Without thermostat water will be flowing in and out non stop, hence the fans would be working non stop. The fans stop working when the thermostat is closed.

Thanks a lot.
Is there any 'simple' test to confirm that the thermostat is not there?

The general rule is this (mostly Toyota's) a.c on fans will be on, when the aiconditioning cool temp has peaked in the cabin, the a.c module will signal the compressor to cut off, which will also signal the fans to stop working (unless if temp is above 90deg)

So OP turn off your ac and leave car running idle, it might take a while but your fans will come on eventually and go off when the fans have blownfor a while.

This will continue weather or not the thermostat is installed, the only diff is that with the thermostat installed the temp rises quicker and you don't have to wait forever for the fans to come up and go off.

GAZZUZZ:
The general rule is this (mostly Toyota's) a.c on fans will be on, when the aiconditioning cool temp has peaked in the cabin, the a.c module will signal the compressor to cut off, which will also signal the fans to stop working (unless if temp is above 90deg)

So OP turn off your ac and leave car running idle, it might take a while but your fans will come on eventually and go off when the fans have blownfor a while.

This will continue weather or not the thermostat is installed, the only diff is that with the thermostat installed the temp rises quicker and you don't have to wait forever for the fans to come up and go off.

Thanks for the insight, from your post I understand that the fan should run intermitently.. Whether the thermostat is installed or not....
My worry here is that through out the period of watching the car.... 10mins with ac (fan ran non-stop), another 10mins without ac and the fan never came on.
Abeg what could be wrong

abatically:
Ur mechanic might be right. The thermostat must have been removed which makes the fan run non stop once ur ac is turned on. The way the cooling system works, when thermostat is open, it allows water from the radiator flow through the engine, which signals the engine coolant sensor and activates the cooling fans. Without thermostat water will be flowing in and out non stop, hence the fans would be working non stop. The fans stop working when the thermostat is closed.

You got it all wrong here .Note that a thermostat is purely a mechanical device which is usually placed along the path of coolant flow.it opens and closes the flow of coolant into the engine based on the attainment of preset temperature. thermostat doesn't trigger fan ,it usually a thermistor named thermo switch or engine coolant temperature that trigger the fan .There are only to condition for the fan to be triggered on :
1.when ac is on : the fan run at relative low speed.
2.when engine temperature is just about to exceed a threshold temperature e.g 96C,100C etc depending on engine type: fan will run at relative high speed.
note that there is no relationship between the working of the fan and thermostat .

oNj:


Thanks for the insight, from your post I understand that the fan should run intermitently.. Whether the thermostat is installed or not....
My worry here is that through out the period of watching the car.... 10mins with ac (fan ran non-stop), another 10mins without ac and the fan never came on.
Abeg what could be wrong

.
For your engine (2ZR-FE) the fan turn- on temperature is around 97 centigrade .You will need to wait long enough for this temperature to attained .However your waiting period will be more elongated if your thermostat has been removed or radiator has been swapped to double cell.
All other things be equal your fan will still eventually come on,just exercise some patience.

honmusa:
.
For your engine (2ZR-FE) the fan turn- on temperature is around 97 centigrade .You will need to wait long enough for this temperature to attained .However your waiting period will be more elongated if your thermostat has been removed or radiator has been swapped to double cell.
All other things be equal your fan will still eventually come on,just exercise some patience.

Thanks a lot, sounds a bit consoling. Will have it connected (thermostat diagnosis/fixing will follow soon).

Was afraid the fan will never run except I use ac..... Overheating wahala.

Thanks for all your contributions, nice having you guys here to fall back on for expert assistance.

oNj:


Thanks for the insight, from your post I understand that the fan should run intermitently.. Whether the thermostat is installed or not....
My worry here is that through out the period of watching the car.... 10mins with ac (fan ran non-stop), another 10mins without ac and the fan never came on.
Abeg what could be wrong

Wait longer, you are impatient.

oNj:


Thanks for the insight, from your post I understand that the fan should run intermitently.. Whether the thermostat is installed or not....
My worry here is that through out the period of watching the car.... 10mins with ac (fan ran non-stop), another 10mins without ac and the fan never came on.
Abeg what could be wrong

I think the double cell radiator is making the wait longer

GAZZUZZ:


Wait longer, you are impatient.

Thanks man.
Hope I don't come back with "stories that touch"

oNj:


Thanks man.
Hope I don't come back with "stories that touch"

Their is nothing to be scared of , just ensure u keep ur eye on the engine temperature guage on your console .It can exceed the middle mark but will not get to the red zone before ur fan come on.