Got a strange noise coming from behind the grill for last two days when car started from cold. It last approx 1 minute or so and sounds like an electric fan. I looked in through the grill and sure enough there looks like there is a fan in there in front of the rad.
WTF, I thought the viscous fan was all that was there. What is this one for and why come on when engine is cold. Did not happen this morning and only difference is that outside temp is cooler than last two days
 Declan
2003 FFRR Vogue 4.4 V8
97 Defender 90 300 TDi

AC fan

The electric fan is for Air-Con and also if the viscous one isn't coping such as a hot day, towing, uphill etc.

On my 2011 S/C the viscous one will start locked and then drop off within 30 seconds or so.

The fan works approx 5-10% of the time only. The fluid is regulated by a bi-metallic strip that responds to the temperature, opening and closing a valve which allows the viscous fluid to flow and engage the fan above normal operating temp.

You can also hear it engaged when the engine is first started. After less than a minute it disengages, any longer and it needs repairing/replacing.

Cheer guys, thanks for clearing that up  Declan
2003 FFRR Vogue 4.4 V8
97 Defender 90 300 TDi