1989 Corolla GT-S engine fan ??

[sty]

As soon as I put the key in the on position , the engine fan comes on , even when the engine is cold. Is this a sensor problem? The car is 1.6litre with fuel injection.
Any and all replies appreciated!
Thanks

[REN69]

Sounds like your sensor is gone.. the sensor is just before the thermostat housing on the pipe, it has a wire going into it.

[Apo11o]

yeah, thats your sensor, at least yours stay on, mine didnt come on at all for a while, drove it short distances for about 2 weeks with that, never again...

Be carfful fixing it, i had mine replaced, and they broke my thermosdat! costing me more money, and yes im sure it worked when i took it in...

[REN69]

I doubt they broke the thermostat.. it probably broke because of overheating. Remember the fan pushes heat away.

[project trueno]

Toyota laid out their fan circuit differently than other manufacturers. Unlike typical fan relays, Toyota chose to got with a NC (Normally Closed) relay, and a NC fan switch (screwed in coolant inlet housing).

When the coolant temp. goes past the "dangerous" reading, the fan switch will internally open, causing a break in the signal side of the circuit, this will trigger the power side of the relay to feed electricity to your fan motor.

Its designed this way as a fail-safe system, when a break in the circuit occurs, its better to have the fan running all the time (engine running) then not running at all. So look for a open circuit, it could be as simple as someone forgetting to put the plug back on the fan switch.


To test the actual fan switch, pull the plug, grab your multimeter. With key in ignition and a cold engine, test the switch for continuity, if its grounded, then your fan switch is fine and you should check out your wiring or the fan relay.

[sty]

Thanks alot for the help!

[sty]

Thanks for the input..changed out the engine coolant sensor , fan now works normally.