Fan issues on 3sfe caldina

[AceSniper]

working on a 3sfe 4x4 caldina 1997, The fans wont switch off...

Relays fine... im sure its the fan temp switch(they turn off when grounding the light-green black trace switch wire)..... But I cant find the temp switch anywere.... only a guage temp and ecu temp senders

Does anyone know where the switch is or what switches them? might be the ecu? but cant find a pinout anywere for a 3sfe (its a later version with coil packs and toothed crank trigger)

[RS13]

*edit* scratch that.. lol

[RomanV]

ECU and gauge sensor will be in the head on the block, temp switch for radiator will be in the bottom of the radiator itself.

From other cars I've worked on, radiator temp switch triggers a relay which turns on one fan only.

Then there's a sensor in the aircon which triggers a relay which activates both fans, when aircon is on.

So if both are going all the time, I'd be checking out the aircon system/sensor.

Could be something else, but that's where I'd start looking.

So (from memory) there will be two relays, one activated by the aircon and one by the radiator temp switch... If this is the case you could pull out one or the other, and see which is making the fans go or not.

If when you've got the aircon one out the rad fans only go on when the engine temp gets up, then you know it's your problem.

[AceSniper]

Nah there is no temp switch in the radiator as iv replaced it (fans were staying on from the start)

Iv done cambelt, tentioners, water pump, front seals,oxy, thermo... and service.... But im yet to find the cause of this fan issue.

I know the fans run through the a/c pressure switch iv had it unpluged... and earthing out the light green black stripe wire the fans turn off (this is the fan trigger wire to the relays)

From my understanding the wire opposite the relay trigger on the a/c pressure switch plug is normally the feed from the water temp switch but this wire is not the normal green/black stripe its blue with a stripe ??
if this is the wire thats ment to control the relay trigger its not working...
but I need to know what the temperature based switching wire is and were its coming from...

If there was a location I could just screw a new fan switch in I could easily wire it in but cant find one

[fivebob]

From the EPC it seems that the 3S-FE equipped 4WD Caldinas don't have a temp switch

As all my wiring diagrams are in Russian I can't say how it works without translating it and that will take a day or so to do.

[AceSniper]

thx... So im guessing the ecu switches it... and cause no body touches 3sfe's cant find a pin out. Have opened the ecu and nothing looked a-miss

[fivebob]

Then FAN pin is on the bottom row of the middle (16pin) ECU connector, 3rd from the left. Should be blue with a white stripe.

Diagnostics say it should be 9-14v when the temp is below 90°C and 0-3v when it's above 105°C.

[AceSniper]

cool thanks for that info will test it when I look at it next, the wire on the other side of the a/c pressure switch sounds like this ecu wire....

Thought it should switch to ground to hold the fans off... if i ground the green/black at the a/c plug they turn off.... unless the a/c pressure switch changes the signal *lost*

[fivebob]

The A/C relays are "Normally Open" relays so they need a voltage applied to close and complete the circuit and turn the fan(s) on.

The water temp relays are "Normally Closed" so they need a voltage applied to open and turn the circuit off. So if there is a break in the wire or fault in the temp circuit the fan(s) will be on. Much safer that way.