What is this fan for --pics inside

[AsphaltAnihil8r]

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1839604722
LOOK AT THE PIC of the RADIATOR--NOT YELLING
I have one of these on my car but have not seen it come on,,what's it for please??:D

[TerryY]

It is the "Auxillary fan"

It should come on in Low speed as soon as the Air Conditioning is turned on.
OR it is turned on by a thermal switch on the passenger side of the radiator when the coolant temperature rises above the switch set points. This has Low/High speeds.

[AsphaltAnihil8r]

Terry,thanks for the info..So when the AC is on the fan should be on low and when the temp rises in the radiator the fan should go to high or is it the other way around..

Also how can I check the fan,,my temp gauge in car never goes past half way,,my fan does not turn on with the AC,,how do I test..

Dennis

[TerryY]

Dennis
Normal operating temp is the needle on the indicator just below or touching the center mark.

There is a connector on the switch on the passenger side of the radiator. If you remove the connector, on the plug you will see 3 sockets.
One of those sockets will be the 12 volt supply.
One is Low speed.
One is high speed.

If you connect a jumper wire from the 12 volts to the other two sockets in turn , the fan should run in low and high speed.

My 740 has a problem with low speed. it doesn't run with either the AC or the jumpered connector in Low.
When it runs jumpered to Hi it blows so hard that the engine driven fan tries to spin!

I will be replacing the low speed resistor on mine soon to fix the problem. (Located behind the grill on the aux fan frame).

The first and most important accessory to buy for the car is the Bentley manual for the 7 series. Shop around for price but assume about $90. It answers a lot of questions with pictures and diagrams.

Terry