how does rad fan coolant temp sensor work?

[gmacrae]

Howzit... i want to get the radiator fan running in my fxgt using the fan temp sensor thats in the silvertop

Currently the sensor isnt wired up to anything, i've just got the relay tripped to run the fan non stop. Does this sensor ground out at a certain temp to trip the fan relay or does the stock ecu monitor it to fire the fan relay? Just wanna know how i should be wiring it to use this sensor to make the fan run only when it needs to.

Cheers

Gene

[barryogen]

along these lines, other than taking a bit longer to get up to operating temp, a bit more drain on however it is run(meaning electrically or crank?), and a bit more wear on it...

is there a downside to having it running all the time?

[gepsk8]

the sensor earths til it reachs temp to turn relay of, get relay is on when keys on turns off when relay reachs temp, if u get that.

[Bumpy]

the sensor earths til it reachs temp to turn relay of, get relay is on when keys on turns off when relay reachs temp, if u get that.

I would say it's the other way round. The sensor earths when engine gets to temp, otherwise if the plug was out of the sensor, fan would go all the time ...

[rollaholic]

it does go all the time when its unplugged.

good way to check if your fan is dead!

[matt dunn]

Correct, the single wire toyota fan switches work the opposire to what you think,

they earth out below the set temp to stop the fans,
which is why unplugged they go all th time,
and the same feed goes through the AC pressure sw,
so if that is unplugged they go also.

[Bumpy]

When I did my clutch on my Glanza, that single fan wire was something I missed, car nearly over heated cause it wasnt plugged in and fan wasnt going at all .... Could it have been something else?

[gepsk8]

what years ur car? as more late models car are now ecu controled.

[Bumpy]

Oh ok, yea it's a '96 Glanza

[gmacrae]

good'o thanks guys