Radiator fan not turning on...

that was not the answer!!

Interesting...that'd be my first guess. This is the one at the bottom left (driver's side) of the radiator right?

I'd still test it out...or the wiring at least. Pull the plug off of the thermoswitch and you should have three wires. One is solid red...that one is 12V all the time. Test that with a voltmeter and make sure it has 12V power. If not, there's your issue...no supply juice. You'll need to trace this wire to find where it comes from (never had to so I don't know for sure where it goes to).

If that works out OK (that wire has 12V power), then make a small test wire and jump the solid red one to each of the other ones in the wiring harness. One should turn the fan on low speed and the other should turn it on high speed. If those work then the thermoswitch is still your issue...you may have gotten a bad one. If those don't work, then you have a wiring issue or relay issue.

Now go up to the fan relay at the top of the radiator. If you look at the top of the radiator, it's on the driver's side near the top. The original one is probably a little metal box with four pins. If it's been replaced it might be a plastic one. You can test this relay out (or just buy a new one...they're under $5 at the dealer...just make sure they give you the right kind (I think they're 40-amp)). Hopefully that relay's the issue ('cause it's a cheap and easy fix).

HTH...

-Matt

Will it turn on if you short the thermoswitch connector terminals? If so, the "new" thermoswitch is bad. If not, there is some problem in the wiring from the thermoswitch to the fan relay or the relay itself is bad. Is it a 1 or 2 speed fan? Get ahold of a Bentley manual and trace the fan circuit.

Maybe you have the same "problem" I had with my 75 Diesel Rabbit. I had it two years before driving through the Mojave desert. When I stopped at a rest area I heard a worrying sound. When I investigated, I found out it was the radiator fan. It was the first time it had come on without the A/C.

It was fun listening to the locals telling the people from out of the area that they could not use their A/C because it was too hot and their cars would overheat as many had. My little efficient diesel had finally got hot enough to turn on the fan.

Diesels are more efficient and the radiator in mine must have been sized for a gasoline engine so it seldom needed the fan.

I might add that it never overheated. Does yours seem to overheat?

I would most likely check the thermostat along with a bit of a rad flush. Sounds like there's something blocking the flow of fluid. If the car seems to run hot then it is most likely the thermostat or a blockage Good luck Paul Ottawa, Canada

Never had a fan problem in a VW, but in most American cars, the fan turns on far above (about 50F) the normal operating temperature (or immediately with the A/C on). Does your car overheat? And when does it not turn on? Mine is off too at the moment.