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[Kevin Wood]

The fans are indeed supposed to run with the A/C on. If the fans don't come on with the A/C off, even when the engine is overheating, and it behaves OK with the A/C on, it points to the fan switch in the radiator. Might be worth removing it and checking that the surface is not contaminated with oil, and if that doesn't help, replacing it.

Kevin

[Albus Dumbledore]

So both fans are supposed to start? Just to clarify : The radiator fan hangs on the radiator (between the radiator and the engine), on the other side of the radiator (between grill and radiator) sits what looks like another radiator (is that the heater exchange?), and on the outside of that again (between grille and rad no.2) sits the other fan (what I call the A/C fan).

Both those fans are supposed to start?

I will check the thermo- switches:) Is there any way of testing them? Dipping them in boiling water maybe, and see if the fan goes on?

[Kevin Wood]

Not sure what fans are supposed to run on a 4 pot. On the v6 there are 2 fans in front of the rad that run with A/C. The one behind the rad. only runs with increased engine temperature.

You can sometimes test a fan switch by suspending it in boiling water but the trigger temperature is so close to boiling point it's not a 100% accurate test. It will certainly need to be in a pan of boiling water for a few minutes to get it to switch.

Best way is to take it off the car and put a multimeter on ohms across the contacts while it's in a pot of water on the stove.

Kevin

[Albus Dumbledore]

Thanks! I will try taking it off and use a multimeter. What is Ohms?? And do you know when the switch is supposed to trigger?

[Andy B]

.....What is Ohms?? ......

Resistance. the symbol is a horse shoe shape, appropiately called Omega.

[TheBoy]

To prove its fan switch (which often fails after getting oil/coolant mix), unplug it and short the loom out with paperclip. If fans come on, then your issue is faulty switch, or the switch isn't getting hot enough.

If you have oil in coolant, Forte do a special coolant cleaning solution that is quite good, call Forte coolant cleaner for oil cooler failures or something.  Forte's normal coolant flush is good for general dirty coolant.

[Albus Dumbledore]

The boy wrote:
To prove its fan switch (which often fails after getting oil/coolant mix), unplug it and short the loom out with paperclip. If fans come on, then your issue is faulty switch, or the switch isn't getting hot enough.
I have tried to short the look, and the fan came on:)

I just read in my Haynes manual, the fan I was talking about earlier, is attached to the condenser

So, when I turn the A/C on (push the button in the car) the condenser fan and the radiator fan starts. Are both supposed to start?
Sorry if I'm nagging, just tired of this problem and don't want to missunderstand

Also (in my head), when the car is almost overheating, and I turn the rad fan on (via the A/C) and the car cools down, that means that there is som circulation. Since the the cooling happens in the radiator, and the temp sender unit is mounted before the radiator (meaning the cooled coolant needs to go through the whole engine to get to the temp sender). Does that seem right? Or am I way off??

[TheBoy]

Not sure about both fans with A/C, hopefully another owner can check.

If the fans can control it, I'd be looking at efficiency of rad.  If fans aren't coming on until 100C, I'd be looking at fan switch.

[Albus Dumbledore]

Today was the first time I could drive the car home since december, the car has been at my parents house (they have a garage, and garden hose) and there was no problems whatsoever:) When I drove on the freeway the air through the grille sufficently cooled the engine down, and when the temperatur went over 90 C, I turned on the A/C and the temp went down again 8-)

So, PROGRESS!!

But, when the car is hot, and I turn it off, it won't start till is cold again.. Sounds like the battery is flat when I try to start again, but I have measure the battery, and it isn't flat?

And, when measuring ohms (resistance), what should the reader show? (I am thinking of the thermo- swiches)