I have a 98 vw jetta gl 2.0 liter engine. My problem is the radiator cooling fans run all the time even when cold. If you turn the ignition on or start the car the fans come on and never kick off. I replaced the fan control module and now the fans run even with the ignition off and the the car not running. I put the old fan control module back in and the fans still run constantly but turn off when you turn off the ignition at least. Please help.
2 possible problems.1) the fan control switch that is mounted in the radiator has shorted closed but 99.9% of the time those switches fail open so the fan will not turn on. 2) when you turn on the AC the fans always come on. So you should check theac control cicuit.
May, 20, 2011 AT 8:46 PM
When you say the ac control circuit do you mean the ac pressure switch or other parts of the ac system? Sorry, I'm good mechanically but terrible with electric systems. I tried a new fan switch that mounts in the radiator and that didn't fix it. I've heard that the ac pressure switch can cause this problem but I don't know where that switch is and I hate to buy anymore parts, I've already spent a couple hundred bucks to no avail. Thanks for your input!
May, 25, 2011 AT 12:05 AM
When I say the ac control circuit, when you turn on the ac @ the dash, it tells the ac control circuit to turn on (ingage) the ac compressor clutch, the cooling fans, interior fan, increase the idle rpm. I belive there are 2 pressure swiches a high and a low which cycles the compressor and shuts it down when pressure is to high or low. A Haynes or Chilton manual would help you as they have schmatics in the last chapter. I can take a look at a friends and see what I can find, give me a few days.