I have a 99.5/2000 Jetta 2.0 that the cooling fans will not come on. I have changed out the fan switch on the radiator on the lower left side after perfoming the Jumper wire test on the fans. They came on when terminals were jumped. I then checked the fuse at #16 it is good, as well as the fuse at the battery. The temp gage is working and I flushed the system and put DEX-COOL in it. The car idles at 190* for about 5-10 mins without overheating, but as soon as I rev the engine a little the temp starts climbing to 230* and the fans do not come on. I shut it down so the engine does not get cooked. Is there anything else to check? Is there a Fan Relay swicth somewhere else that is not shown. Please advise! Thanks

 

there are relays to the fan switch they are useally in with the fuses (they look like 1 square inch boxes plugged in where the fuses go) mabey get anchiltons or haynesmanual to see what one it is and try and replace it. or it might be the thermostat it self, like its stuck closed or something

 

I think the temp sensor is wired into the fans. When the temp reaches a certain degree the fans will come on, so I think there is another sensor that may be bad but you'd have to go to like ALL-DATA to get a schematic diagram.