Fans always running on my VW Jetta 1995 2.0. It doesn't matter if I start up cold engine or not. I checked sensor by unpluging them one by one but fans were still running. I found only one way to stop them just to unplug power connector

The fans are getting a constant live feed so they can't turn off. Start by rechecking the wiring and the connectors for the fans and the sensor.

The fans are run by rad temperature, not engine temp on a VW.Somewhere on the rad you should see a wire harness plugged into it.That is a thermo-switch which turns the fans on and off based on coolant temp in the rad. My car is a lot older than yours but this switch is virtually hidden on the bottom driver's side of the rad. It has 3 wires going into it.There could also be another sensor attached to the engine block or head to monitor engine compartment temps after engine shut off. This will turn the fans on or off as well based on air temp in the engine compartment.

Here's the link and I'm sure you will get the solution of your problem 1999 volkswagen

check the relays for your fans and check you fuses for yourfans

sounds like the fuel pressure regulator but first try new fuel filter and maybe clean spark plugs and reset them

Try changing the fuel filter.

try checking the throttle position sensor or the idle control valve both can keep it from running.

you have a stuck fan relay that needs replacement.  It's in your fuse box.

disconnect the cooling fan temperature sensor on the engione that turns on the fan, if the fans runs the switch/sensor is defective.

check gas cap . use scanner when check engine light comes on you got a problem some where . scanner will give you a code . you got a bad sensor . fix it . the scanner will have to erase code.if you dont repair sensor .the check engine light will stay on.