cooling fan coming on late

[jade]

Just to confirm, it is the multi sensor on the water rail that controls the cooling fan

[twoqu]

No!
The fan is controlled by the temperature switch in the radiator. It has two temp on/off stages.

[UrS4boy]

No! The fan is controlled by the temperature switch in the radiator. It has two temp on/off stages.

Generally true except the after-run pump and fan are triggered by the two pin switch on the water manifold. Turning on the A/C will also start the fan in most cases.

http://forums.quattroworld.com/s4s6/msgs/21503.phtml

[jade]

Ok, Thanks could not remember which one it was, Yes I am needing to switch the A/C on for the cooling fan to work

[twoqu]

If you can get to the wiring connector at the switch you could jumper between the terminals. One should have battery voltage on it,another operates the second speed fan (the first being the a/c) and the other one should be the third stage. If the fan works on both its likely to be the switch. Other than that it could be relays/fuses/wiring/resistor pack etc.
Keep away from the fan when doing this for obvious reasons!