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radiator fan doesnt comes on till I turn ac on

radiator fan doesnt comes on till I turn ac on

radiator fan doesnt comes on till i turn ac on.

Asked by: Guest | Views: 222
Total answers/comments: 4
bert [Entry]

"@fusebox. sounds like a bad thermoswitch. Here is the explanation why it comes on with the AC:""

The electric radiator cooling fan assembly is controlled by a thermoswitch located in the side of the radiator. At higher coolant temperatures, the switch closes to start the cooling fans. Any time the coolant temperature rises to higher than normal levels, the fan will start and continue to run until coolant temperature returns to a normal range. On vehicles with air conditioning, rising refrigerant pressures will also activate the cooling fans.

Attached documents will show you how to test the switch etc. Fan-and-Thermoswitch.pdf"
bert [Entry]

Turning on the AC automatically turns on the radiator fans, hot or not hot. In order for the AC Condensor to do its job it must stay as cool as it can. As for the engine coolant temp sensor, if the coolant is not hot enough to make the fan come on, then there is no need for the fan yet and there is no problem. Simply the engine is not hot enough to turn on the cooling fan, its not hot enough outside, you are driving getting plenty of air flow through the grille to keep things cool without the assistance of the fan. Its possible that you have no problem at all.
bert [Entry]

"Have you checked the fuses in the black box on top of the battery. Those steel like fuses.

Fuse 16 on the side of the dashboard.

When opening the cover it will be the 2nd fuse from the top left.

https://knigaproavto.ru/shemy/en/volkswa...

It is for the fan module. When the ignition is on and you pull it the fans should kick in and turn slow speed.

You can also put direct power by pulling the fan plugs and putting on power and ground to them. Fast speed and slow speed, fan should start turning.

https://forums.vwvortex.com/showthread.p..."
bert [Entry]

"You might have an initial temperature sensor which causes the fan to come on when the temperature begins to rise; that sensor might be defective.

Then when you turn the A/C on, the temperature goes up even higher, which triggers the next sensor.

I would look for an initial, ""low temp"" sensor that is defective."