radiator fan running

[Smaay]

well I got Amy's car back up and running (kinda) as soon as I put the key in the ON postion, the fan comes on. im also getting a code for coolant temp sensor. do I have the plugs backwards on the water neck?

[RedCelicaTRD]

I know on my harness the plugs do not match the sensor color, they are backwards. The fan issue could also be the fan switch in the bottom of the radiator. When they fail the fan is always on.

[underscore]

The switch for the fan is in the rad, not the coolant neck (it's on the bottom, make sure one of the wires isn't broken right at the plug like mine was). The two in the coolant neck shouldn't be able to be backwards as the plugs are different.

[Smaay]

ok so if its the switch at the bottom of the radiator, how do it check it? is it a simple ohms check on the sensor?

[FC Zach]

Also if your ac pressure switch is not connected, the fan will run.

[Smaay]

yeah i knew that, its plugged in, when i unplug it, i can hear relays clicking.

[underscore]

It's an open/closed switch, it should open when it gets hot

[RedCelicaTRD]

I believe it opens when it gets hot. This is why the fan turns on when you unplug it or the AC switch.

[underscore]

Sorry, you're right, I got it backwards.

[Smaay]

checked the switch, it has continuity through the pins so i know its closed. havent checked the AC switch yet.

what else can it be?

[warracer]

Probably the AC switch at this point . Mine failed and the fan was on 100% of the time, I deleted the AC and now my fan runs all the time. I don`t really mind since these engines tend to run hot anyway. You could add a manual switch inside but there`s always the risk of forgeting about it and letting the car over heat. I`ve been driving the car with the fan always on for the past 2 years, not a single issue, in the winter when its -25C or colder the engine doesn`t run at the prefered thermostat temp but I still have heat and the afr is steady 14.7 so it doesn`t run lean or rich.

[Smaay]

id rather not have the fans running all the time. ill try to figure it out

[mx6er2587]

you could always just wire a universal controller if you can't get the factory one working

for example: http://www.summitracing.com/parts/der-16749/overview/

[Corey]

Probably the AC switch at this point . Mine failed and the fan was on 100% of the time, I deleted the AC and now my fan runs all the time. I don`t really mind since these engines tend to run hot anyway. You could add a manual switch inside but there`s always the risk of forgeting about it and letting the car over heat. I`ve been driving the car with the fan always on for the past 2 years, not a single issue, in the winter when its -25C or colder the engine doesn`t run at the prefered thermostat temp but I still have heat and the afr is steady 14.7 so it doesn`t run lean or rich.

Check out www.gtfours.co.uk for a how-to on deleting the a/c and modifying the a/c pressure switch so the rad fan doesn't run constantly. I think i just left mine plugged in when I deleted my a/c.