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fans

Is your aircon working? Low refrigerant pressure can lock out both fans. I'm not sure if you have seen this http://pics.tdiclub.com/data/516/A4_Coolant_Fan_testing_Rev_7.pdf. It might be worth scanning the car and look for an error code on your A/C switch. Could be intermittent.
It's the other way around I believe. When one or both fans don't work the condenser get's no air through it and so it's high pressure rises to above 300psi really quick(seconds) and disengages the A/C clutch.
 

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thermo switch

I do not think the 1.8t has a temp sensor in the lower radiator hose, or at least not all 1.8t configurations. The temp switch for the fans on my 1.8t is forward of the main coolant sensor in the manifold on the drivers side plastic manifold connected to the cylinder head.

This is the fan switch location in my 2003 1.8t:

http://newbeetle.org/forums/774839-post17.html

http://newbeetle.org/forums/1-8-liter-turbo/18279-what-sensor.html
It's actually mounted on the radiator and by the lower hose and it's called thermo switch but in reality it turns the fans on with either temperature rising or with the A/C push button on and at least one blower setting on. There is a coolant temperature sensor by the plastic flange and that one provides data to the CPU and also turns on the fans via the FCM if required. The one sensor closest to the Battery on a "Y" hose connection is for the 3rd speed relay which turns both fans at their highest speed via the FCM.
FYI; The picture you posted with #2 in green is the so called third speed thermo switch.
 

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My Beetle is 1400 miles away, so I do not have access to it.

Did not recall seeing the other sensor in the radiator, but checked the picture of the radiator and now see the threaded boss.

So it looks like there may actually be 3 different sensors.

Not sure what sensor runs the fan(s) when the car is shut down, assume it may be the sensor in the radiator? I have not dug out the wiring diagram to see how all of these sensors work together.

Often a sensor near the lower radiator hose is considered a radiator outlet temperature sensor on some models.
 

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sensor

My Beetle is 1400 miles away, so I do not have access to it.

Did not recall seeing the other sensor in the radiator, but checked the picture of the radiator and now see the threaded boss.

So it looks like there may actually be 3 different sensors.

Not sure what sensor runs the fan(s) when the car is shut down, assume it may be the sensor in the radiator? I have not dug out the wiring diagram to see how all of these sensors work together.

Often a sensor near the lower radiator hose is considered a radiator outlet temperature sensor on some models.
You assumed correct, it's the one on the radiator that runs the fans in low speed for a few minutes after you turn off the car depending on the coolant temperature.
 

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Srhubs

Sorry, did we answer your questions Mr srhubs? Didn't mean to hijack your thread just clarifying a few things about the electrical fans in these cars.

Thanks

Julian
 

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Hi All,

I need your help. I have a 2002 1.8 turbo beetle and I have sold it to somebody who was not able to pay me and so I got back the car after 8 months of him using it. When it returned, there were a lot of errors when I scanned it with the OBD scanner. He said he had rewired everything from a Nissan technician. We saw that he tapped some of the sensors for power. We also replaced the fuses on the fuse box but when we did that, when we turn off the ignition, the engine would still run and we had to improvise a switch to turn off the engine. The cold coolant indicator also does not turn off and so it looks like I still have cold coolant even if I had done 100kms! The battery also runs out even if you are not using it so it means there is a ground somewhere.

Please help. I want to restore my beetle to what it was previously. I had found a guy who can help me out from VW but when we checked the chassis number on their system, it was blocked so he cannot see the wiring diagram for my beetle and we cannot find any other 1.8 Turbo's chassis number here in the UAE to look at the diagrams.

1. Can anybody send me all the wiring diagram for a 1.8turbo beetle?
2. If anyone can send me their Chassis number so that we can check it in their system and just print it from there.

Really appreciate your help. Thank you so much everybody!
 

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Volkswagen Workshop Manuals

As for VIN, suggest you search ebay listings, for sale adds and try to just modify the VIN entry you are using. Not sure many people will send you their VIN.

As for the fans, they should run at low speed when the AC is turned on even if the engine is not running. If not, the fan control module that is located on the right front of the battery tray often fails around this age. Mine recently failed and when it did the AC would not work, the fans would not run and I do not think the turbo coolant after pump ran either.

You also need to make sure fuse #12 a 7.5 Amp fuse is installed and not blown. This same fuse provides power to pin #16 on the OBDII connector.
 
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