Thermo fan help.

[ScienceVR6]

After fixing my clutch fork last weekend, my thermo fans won't turn off. They just stay on while the motor is running.

Also the outside temp tells me its 50 out side. All the time.

Now i belive these are related.
I think the car thinks its hot out and takes the precaution of turning on the fans.

But its like 10 deg here now.

I did some tests.

At room temp, the multi meter read 3.5k ohms. When rapped in my hand,it read lower. I assume the sensor works.

Whats wrong with it?

[h100vw]

Have you got all the earths fitted back in their respective places?

The other thing I'd look at it the switches, for being stuck in the closed position.
Possibly even the Aircon control. Pull the aircon fuse and see if that does anything.

Gavin

[ScienceVR6]

good idea with the ac bit.
i'll try.

is there a fuse for the temp sensor somwhere?

[Elwoods 2LGL]

Thermo fan issue fix posted on vw vortex

Not sure if this is the same as your issue
Mine used to run the battery flat unless I unplugged it each night

Ive coppied this from my post of VW vortex
-------------------------------------------------
My fan issue has been sorted
Its taken me 2 years, 2 Fan Controllers and a thermo sensor to find it was a dodgy connection.
I Followed the wiring back to an "Air con/Temp sensor"connection located right near the front wheel and fiddled with that connection and the fan finally came good.

I was messaged by someone here on vortex who had the same issue
(it slips my memory who - im trying to remember I would like to thank you very very much. ( im sure my neighbours would also like to say thanks)

Yeah
--------------------------------------------------

Hope it helps - if not go to vortex and search thermo fan as there are heaps of answers listed

[The_Hawk]

AC Pressure switch??

My fans used to run 100% whenever the car was on, then the afterun would kick in whenever you turned the car off regardless of actual temps. I had a big manual switch put in so I could manually turn off the 100% fan setting, but I had to remember to turn it on if I flogged the car (or it was hot).

I tried different fans, different controllers and different sensors. FYI, you can test sensors just by plpugging them in (not installing them) as they will read room temp which will always be low enough to NOT turn fans on (in theory) so you can skip the sensor as the culprit.... beats pulling everything apart and catch/replacing fluid time and time again.

Anyway, long story short, when I replaced the compressor and the receiver/dryer and the pressure switch on that I noticed the fans were now working as intended so I have had my big ass switch disconnected (gotta work out something I can hook that up to...) and it all is working fine.


As for the MAF reading 50C, I have NEVER had that sensor in my car and it used to always read 50C or just skip over it like that option didn't exist on the MAF... I can't confirm since I never bothered testing it, but I believe that it skip it when there is NC and reads 50 for a short.

You need to remember the VR6 has about 5 temperature sensors all of which seem to work indepentantly so I don't know that your outside temp issue is in anyway related to the thermo fan problem.

From memory:



Yellow is for the thermo fan afterrun feature (and highspeed while running), it's a 4 pin plug (I don't think the "new" sensor is yellow anymore if you buy it from VW).
Blue is a two pin and is for the temp guage in the cluster.
Brown... I don't remember anymore but I think that one is for the ECU.

There is also the 4 pin plug on the radiator (I have a brand new one of these sitting on my desk which I never needed if you want to score one on the cheap).
Then there is the little one in the front air dam for ambient temp.

And if you want to get technical I believe there is another air temp in the air filter housing for intake temp.


This all brings back nightmares from when I had issues with mine and poured over and over the wiring diagrams trying to work out what was what and what controlled who...

[mk1turbo79]

Yellow is for the thermo fan afterrun feature (and highspeed while running), it's a 4 pin plug (I don't think the "new" sensor is yellow anymore if you buy it from VW).
Blue is a two pin and is for the temp guage in the cluster.
Brown... I don't remember anymore but I think that one is for the ECU.

This all brings back nightmares from when I had issues with mine and poured over and over the wiring diagrams trying to work out what was what and what controlled who...

Yellow plug is actually gauge sender and something
Blue plug is ECU temp sender
Brown is A/C high temp cut off and either high speed (3rd speed) or after run pump switch.


Science; have you checked whether the sensor in the front RH lower grill is plugged in?, i know if they are not plugged in on T4 caravelle and T5's the fans will stay on with ignition.