Cold engine, ignition only, radiator fan stays on

Not getting much electrical luck this last week!

Sticking relay.

Grearvf idea. Thx, I can swap one over and test.

Cannot identify a relay for this.

I guess it could be a thermostat somewhere. I find it so tough working on this van without wiring diagrams/manual.


If anyone else could check this on their super custom>>

With a cold engine

Turn the key to first position - fan on radiator goes on? (doesnt on mine)

Turn key to next position ready for ignition - fan on radiator goes on (does on mine - i'm semi sure it didn't used to?!)

thx

Much sympathy i now were your at it could be the relay or temp sensor or just a wiring fault or not sure if its controlled by the ECU my fan only comes on with AC presumably to assist the condenser that is above 2nd radiator , there are two fuse boxes with relays one by the drivers left foot and on passenger side look on the back of the cover it is usually marked AC .

thx,

Well there is something hanging snapped  in half (a plug with a wire hanging out of it) looks like it came from below coolant lid... gotta be a temp sensor

I recall that one of the sensors around the little filler cap on the 1kz controlled the electric fan for extra cooling.
I remember this because I was playing about trying to find the temp gauge sender and one time I'd disconnected a different one - and the fan started as soon as I turned the ignition on.

As I recall it was just under the filler pipe.

I could research this a bit more if need be, but check the wires going to sensors on the LHS of the engine head water outlet on the front LHS.

Thanks.

What I found >This looks like it could possibly be the culprit.




No idea of part number, does't even show here:
https://www.nengun.com/oem/parts/MTE5NzI2IC0gSXpMd241cUFNREF4OEotYWdURTJNREV3TlVZIC0gUmFkaWF0b3IgJiBXYXRlciBPdXRsZXQ=

Anyone with any idea of how to track down part no after a couple of hours searching. (top right part in picture - 1 brass pin inside), let me know.
I checked prados 1kz-te - different :-(

Good photo, yes that looks like the place I remember, if I left it unplugged from the sensor the electric fan would always spin.

BTW your power steering fluid reservoir has a delicate metal strainer half way down, if it clogs up the fluid them comes out of the top - so I'd check that - possibly vacuum it gently with an oil vacuum drainer - as it should be dry.

Where does that orange/brown wire go? I thought the other sensor was very close, use a small mirror to see if you can find it.

I'd look hard for another sensor, I'll try to get to my van and take a pic later, I have to go out for a walk now (orders from her indoors).

Ok, looking at your photo at the very tip of your arrow looks to be a green thing, I think that is the other half of a disintegrated sensor.

So that's why it's failed.

The other lead (black) must be for something else, maybe the water sensor at the bottom of the diesel filter.

So you need a new sensor and to get the old one's remains out!
I suspect it's a commonish Toyota part, usually on, goes open circuit at 100C or something.

So yes I think that's it, and you'll have to get the remains out carefully first, which will give you the thread size. I think this will be a common toyota part TBH, it's just a NC (Normally closed) temperature switch.

I think if you earth the bit still in the grey connector (via a 1V festoon lamp for safety) to earth the fan will stop.

E.g:
https://duckduckgo.com/?q=Toyota+temperature+fan+sensor&atb=v38-7as&iax=images&ia=images

thx,

I spent a couple of hours looking, can find very similar but not the same.

This has 1 pin, the similar toyota ones have 2.

Anyone with any clues, greatfully received.

Hundreds of dollars from japan, nowhere else has th em.. seems prado/ smurfs did not use these! Soo expensive

Might have found one from wreckers I hope.

They are all the same, just a fan thermoswitch.

I would concentrate on the water/coolant side for thread fit and shape, and maybe adapt the electrical side. 2 pins is the equivalent of grounding 1 pin, then the other is the single pin you need.

So I'd look for something you can make work, no point in spending more than you need.