vauxhall omega radiator cooling fan / over heating problem

Hi, I have an Ecotec 2.0iCDX 1997 model omega with climate. In the last
few days i have noticed that the temperature gauge is hitting 95+ to
100+ degress when the aircon is on, and at times the warning light
comes one..if i turn the aircon off then temperature settles back
towards 95. Under the bonnet the main radiator fan (between the
radiator and engine block) is not turning, however the fan near the
front of the car (aircon fan/auxillary fan I presume) is turning and
speeds up when aircon is turned on and still keeps running when i
switch the aircon off and hence temperature comes down.

Noticed that when I start the car from cold, the main fan comes on for
a couple of seconds and then cuts out - i presume this is some sort of
diagnostic check.

I can only see one temperature switch on the radiator, if i short this
switch then the auxillary fan comes on but the main fan does not...so I
gather that the switch is functioning properly.

My understanding is that the main fan should come on first (triggered
by the rad temp switch) and the aux fan should come on for just the
aircon. So, does anyone any idea as why the main fan is not coming on?
As the fan is coming on from cold I'm assuming all fuses/etc are ok and
its is possiblly some sort of switched circuit that is not working - a
relay maybe? any ideas which one it could be in the fuse box?

any help would be greately appreciated. thanks.

Jazzy

 

Check the fuses in the main fuse box under the bonnet.

 

All fuses are ok.