radiator fan not working engine over heating help asap

Hi there i have a mk1 golf gti convertable 1990
the radiator fan is not working at all when the engine is running so it is getting to hot
i have checked the fuses and also put a live to the fan and the fan works fine at slow and fast speed and the temp on the dash is working fine and the oil temp on the computer but it does go high upto 9.8 and then water temp light comes on so had to stop as not to boil it.
can you please help me with this problem if anyone has had the same fault before i am not sure if it runs through a relay at all if it does which one?
Thanks very much tom.

Have you checked the radiator fan switch? it should have an ignition feed to it and then it will  switch the fan directly!

Maybe the thermostat as this was the prob with my 83 tintop and did check the switch..

where abouts is the fan switch located thanks

where about's is the fan switch located? thanks

in the radiator, screws into the back of it

with a three pin plug?
ps what sort of temp should the oil be at once at normal running on the dash computer?
thanks mate

108 ish dependant on type of oil you got and what oil cooler

it seems to sit about about 96 under normal driving is that to low?

sounds about the right sort of ball park for air/oil cooler:-)