[TR] TR4 cooling

[diggle at clear.net.nz]

Electric fan, heres the update.
I ended up having my radiator reconditioned and the crank
hole put back.
The crank hole blocks off about 15% of the cooling. I
installed a 10" high performance electric fan (biggest that
I could fit) with thermostat, on the front of the radiator
and removed the TR6 fan I had. The power on temp is not
exact with the fan coming on over a widish range. I think
that it might be draining the battery but am not really
sure. If it is I will install an alternator with the wide
pully from the generator. Overall it was a very worthwhile
modification with no more overheating in stop start traffic.
I would like to install an overide switch for the fan but
have lost the info on how to wire it in so will google. 
PS I read that our water pumps don't pump at low revs hence
they contribute to overheating, can they be modified to fix
this problem?