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Oem fan switch mk3 vr6 temp?


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  • 2 weeks later...

I had loads of choices with my 2 cars - all the cooling issues in the end down to the fan switch on the radiator. Original temp ratings are 84-95 / 102 deg C for the 3 pin 1H0959481B fan switch with the squareish plug. It's under a lot of switching load, and the contacts burn out internally. If you're in the states, Rock Auto sell the VEMO V159919771, it looks right and has goth the right temp switch points - just check that your fan switch plug is the squareish (not triangle) one.

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18 minutes ago, chalkyh said:

I had loads of choices with my 2 cars - all the cooling issues in the end down to the fan switch on the radiator. Original temp ratings are 84-95 / 102 deg C for the 3 pin 1H0959481B fan switch with the squareish plug. It's under a lot of switching load, and the contacts burn out internally. If you're in the states, Rock Auto sell the VEMO V159919771, it looks right and has goth the right temp switch points - just check that your fan switch plug is the squareish (not triangle) one.

Thanks i got one but having same issue .

Can u tell me if your fans run after every run? Mine come on stage one then don't shut off till car is turned off and wait the 5-10min then they shut off.is this normal? Replace everything now thermo switches and the radiator switch and the fcm all new hoses and thermastat and water pump.

Thanks

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Stage 1

Controlled by the temp sender in the rad, directly to the fans

Switch On: 92-97 C (198-207 F)

Switch Off: 84-91 C (183-196 F)

 

Stage 2

Controlled by the temp sender in the rad, combined with info from the yellow temp sender via the fan controller

Switch On: 99-105 C (210-221 F)

Switch Off: 91-98 C (196-208 F)

 

Stage 3

Controlled by the black coolant temp sender, via the fan controller

Not listed in the guide above, but it kicks in at around 110-115 C.

For non-AC cars, stage 3 should never come on under normal conditions, if it does, you have a problem.

 

Temp senders

The coolant warning light is actually a level sensor (those 2 metal spikes in the header tank are what the plug is for and measure yes/no on coolant level). There is no over-temp warning other than the gauge going up/big cloud of steam coming out of the engine bay :lol:

 

The main fan control temp sender is screwed into the radiator. This is a 3-pin brass jobber and has 2 different pin layouts depending on if you have early/late VR. It looks like early ones are all 3 pins in a row, late ones are 3 pins in a triangle shape.

 

One pin (not sure what colour, probably brown) is earth.

 

Pin 2 (thick red) is stage 1 output and is full-current to the fan. It has the following switching temps:

Switch On: 92-97 C (198-207 F) - officially rated at 95 C

Switch Off: 84-91 C (183-196 F) - officially rated at 84 C

 

Pin 3 (thin red/black) is stage 2 relay-switched output, which has the following switching temps:

Switch On: 99-105 C (210-221 F) - officially rated at 102 C

Switch Off: 91-98 C (196-208 F) - officially rated at 91 C

 

There are also holes for another 3 temp senders in the thermostat housing. There will be 2 or 3 senders plugged into them as thusly (from left to right looking at the front of the engine):

 

Yellow, 4-pin plug. VAG part number 701 919 369 D(about £20, plus O-ring N 903 168 02)

Coolant gauge, fan control unit and aux water pump (always there)

Switches on: 101-107 C (214-225 F)

Switches off: 94-100 C (201-212 F)

 

Blue, 2-pin plug. VAG part number 025 906 041 A (about £8, plus O-ring N 903 168 02)

ECU (always there)

 

Black or brown

Black, 2-pin plug. VAG part number 357 919 369 F (about £6, plus O-ring N 903 168 02)

For a late-spec 3 stage fan control (or auto gearbox for some reason) and switches on at approx. 112 C

 

Brown, 4-pin plug. VAG part number 357 919 369 E (about £8, plus O-ring N 903 168 02)

Only if you have AC. This is (apparently) a 3-stage sender (i.e. you get 5 stages in total! :lol: ) - VAG part number 357 919 369 E

Don't quite understand the numbers in ETKA for this, but needless to stay, the first of the stages also switches on at 112C

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19 minutes ago, VR6Pete said:

Stage 1

Controlled by the temp sender in the rad, directly to the fans

Switch On: 92-97 C (198-207 F)

Switch Off: 84-91 C (183-196 F)

 

Stage 2

Controlled by the temp sender in the rad, combined with info from the yellow temp sender via the fan controller

Switch On: 99-105 C (210-221 F)

Switch Off: 91-98 C (196-208 F)

 

Stage 3

Controlled by the black coolant temp sender, via the fan controller

Not listed in the guide above, but it kicks in at around 110-115 C.

For non-AC cars, stage 3 should never come on under normal conditions, if it does, you have a problem.

 

Temp senders

The coolant warning light is actually a level sensor (those 2 metal spikes in the header tank are what the plug is for and measure yes/no on coolant level). There is no over-temp warning other than the gauge going up/big cloud of steam coming out of the engine bay :lol:

 

The main fan control temp sender is screwed into the radiator. This is a 3-pin brass jobber and has 2 different pin layouts depending on if you have early/late VR. It looks like early ones are all 3 pins in a row, late ones are 3 pins in a triangle shape.

 

One pin (not sure what colour, probably brown) is earth.

 

Pin 2 (thick red) is stage 1 output and is full-current to the fan. It has the following switching temps:

Switch On: 92-97 C (198-207 F) - officially rated at 95 C

Switch Off: 84-91 C (183-196 F) - officially rated at 84 C

 

Pin 3 (thin red/black) is stage 2 relay-switched output, which has the following switching temps:

Switch On: 99-105 C (210-221 F) - officially rated at 102 C

Switch Off: 91-98 C (196-208 F) - officially rated at 91 C

 

There are also holes for another 3 temp senders in the thermostat housing. There will be 2 or 3 senders plugged into them as thusly (from left to right looking at the front of the engine):

 

Yellow, 4-pin plug. VAG part number 701 919 369 D(about £20, plus O-ring N 903 168 02)

Coolant gauge, fan control unit and aux water pump (always there)

Switches on: 101-107 C (214-225 F)

Switches off: 94-100 C (201-212 F)

 

Blue, 2-pin plug. VAG part number 025 906 041 A (about £8, plus O-ring N 903 168 02)

ECU (always there)

 

Black or brown

Black, 2-pin plug. VAG part number 357 919 369 F (about £6, plus O-ring N 903 168 02)

For a late-spec 3 stage fan control (or auto gearbox for some reason) and switches on at approx. 112 C

 

Brown, 4-pin plug. VAG part number 357 919 369 E (about £8, plus O-ring N 903 168 02)

Only if you have AC. This is (apparently) a 3-stage sender (i.e. you get 5 stages in total! :lol: ) - VAG part number 357 919 369 E

Don't quite understand the numbers in ETKA for this, but needless to stay, the first of the stages also switches on at 112C

I get this and have done and been through all of it over this the last six months .

THE ONE THING NOBODY WILL TELL ME IS HOW DOES THERE VR ACT??? OR 

iS THIS NORMAL ??

Since thr vr6 runs hot and the stage one comes on at around 197 and the car runs inbetween stage 1 and 2 then 1 would always be on.

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29 minutes ago, Vwmk3vr6 said:

I get this and have done and been through all of it over this the last six months .

THE ONE THING NOBODY WILL TELL ME IS HOW DOES THERE VR ACT??? OR 

iS THIS NORMAL ??

Since thr vr6 runs hot and the stage one comes on at around 197 and the car runs inbetween stage 1 and 2 then 1 would always be on.


I think it depends on many factors to be honest. 
 

like health of your water pump, coolant system, health of sensors etc..
 

I always found my VR6 mostly would be stage one / stage 2 after giving it a bit of welly also had a new radiator fitted too (copper core).
 

My oil temps were quite high too and then I got a new oil cooler and temps dropped by 20 degrees!

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Agree with Pete there absolutely, and there's lots of variables.

 

Yep, in answer to your original question, are the fans running after every run: NO. But, if I've been stuck in slow traffic, the ambient temp is greater than 25deg C or it's been driven like a VR should, YES, so as Pete says - it's dependant on lots of factors. These cars are old now, and to get one of mine right (with only 62k and dealer history) it took: crack pipe, thermostat housing, thermostat, radiator upper hose, main radiator, both temp switches on the thermostat housing, radiator fan switch - all to original specs - so no lower temp thermostat or switches. That sorted that one, my other 89k car needed a main radiator and fan switch (that car would get really hot before the fans cut in, over 105 deg C) and oil cooler heat exchanger. A lot of the problem is caused by the old antifreeze G11 or G12 that turns to silt / coating - it reduces the heat transfer through critical components and really reduces the efficiency of a radiator.   

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