Cooling Fans and scavenger Fan

[PaulD]

Hi all , I’ve never heard my scavenger fan come on even after a run in the hot weather we had recently, so I thought I would test it with a 12v supply direct to , the fan worked , is the scavenger fan meant to come on with the radiator fan ? Also when the radiator fan comes only one works , should they both come on together ?
Thanks
Paul

[g8dhe]

No the scavenger fan only comes on when the engine compartment gets to hot, its sensor is under the handle of the handbrake so it justs measures the air temperature in the engine housing, it only operates when there is minimal air flow, like at a standstill in a queue after a long run or similar.

[PaulD]

Thanks Geoff
That makes sense , what about my radiator fans , should they work together, currently only one works
Paul

[g8dhe]

They should work together as a pair for any vehicle type.
For the petrol's they just have one speed on or off!
For the diesel they are dual wound motors with two speeds off, low and high speeds.

[PaulD]

Thanks again Geoff