Fan running all the time

[leemullan16]

hello i took the nob out for a spin today and noticed the fan was running all the time, it wasnt at first when it was cold out the garage but when i put it back later i noticed it running all the time and the temp gauge wasnt even hot, just wondered if anyone else has had this prob?? also where to start relay or temp sensor?? thanks

[Gadgeroonie]

is it a 2.5 or 3.0 ?

i think the 2.5 uses a fan switch

is the water level ok

[leemullan16]

yeah its a 2.5 and the water is fine, would the switch be located under the dash??

[daddysumo]

Check you have not got the air con switched on.

[Urbalizer]

not sure if the temp sensor gives an accurate reading, they wrote the program in the ECU to hold the temp at 90 on the later models, but not sure at what year they started doing this, but basically the car could have been overheating if it has the ECU program and you wouldnt know about it by looking at the temp gauge.

Was the coolant circulating ok back into the header tank?

I'm just wondering if you could have had some ice blocking a coolant pipe, was it cold enough to freeze in the Uk last night, i would be careful running the car until you are sure it is a faulty switch.

[leemullan16]

yeah the car its running fine i know its not getting hot ,def no ice in the system the water is flowing correctly, the fan is just running all the time and i wanna know where it is getting its signal to run because im thinking a dodgy temp sensor... does the whole system only run on one?? i will investigate a little more when i have some free time, thanks for the info they people!!

[leemullan16]

ps i dont have air con fitted its an old skool gto

[mgbond]

The temp sensor/switch is on the drivers side of the rad pipe by the air horn. There is a bit of pipe with a sensor screwed in. If you disconnect the wires to it the fan should stop. If not then the relay may have something wrong with it (that is in the car I think).

The 2.5 doesn't have the temp holding at 90 like the other cars (unless the control has been taken over by the ECU when the upgrade was fitted). Are you running an MBE or still the merelli?

Bondy

[leemullan16]

i will try that tommorow, im not sure which ecu im running, i wish i did i dont know where it is located in the car!! so if i disconnect the sensor it should stop and if it does stop then the sensor will need replacing, if it still continues to run then i will hunt about for the relay. thanks for the info

[mgbond]

leemullan16 said:

i will try that tommorow, im not sure which ecu im running, i wish i did i dont know where it is located in the car!! so if i disconnect the sensor it should stop and if it does stop then the sensor will need replacing, if it still continues to run then i will hunt about for the relay. thanks for the info

ECU is in front (behind panel) of drivers rear wheel.

[leemullan16]

i need to service it soon so i will have a play about with it then. thanks for the help.

[andygtt]

leemullan16 said:

i will try that tommorow, im not sure which ecu im running, i wish i did i dont know where it is located in the car!! so if i disconnect the sensor it should stop and if it does stop then the sensor will need replacing, if it still continues to run then i will hunt about for the relay. thanks for the info

could be a relay as apparently these go causing the fan to run run all the time even if the engines not running or even been started... turn the heater on and the fan goes off and into normal mode ie only comes on when the car needs it.

[Urbalizer]

So do the old school Gto's have 1 fan or 2? If 2 with no air con, do they both come on at same time?

[mgbond]

Urbalizer said:

So do the old school Gto's have 1 fan or 2? If 2 with no air con, do they both come on at same time?

2 but they did not have the shroud this was an upgrade. Both fans come on at low RPM when air con is on.

Bondy