it works!!!!!! problem solved after all that, runs fine, fan cuts in and out like new ad engine runs at a constant temp. thanks everyone for your input and advice.
it works!!!!!! problem solved after all that, runs fine, fan cuts in and out like new ad engine runs at a constant temp. thanks everyone for your input and advice.
what i did was i shorted the switch and taped it in place so fan stayed on and then took her for a 25 mile drive, when i got back i opened bleed and kept topping up coolant with a different colour and kept bleeding till it came through all new colour.....after about 10L there was a big gulp sound and an air bubble came up through reservoir.....so in short an air lock that i didn't get rid of with two bleeds. as soon as it burped the fan cut straight in and has been working fine since