Changed a few bits now the fan won't kick in

[Dre5gtt]

I changed my header tank and a few other pipes and bleed the system ( I think )now when reaching temp my fan is not kicking in and my middle vents blow out cold and the side ones hot air lock ?

[Bigfoot]

Centre vents are cold air vents. Is the rad getting hot? Bridge the plug for the rad fan switch does that come on. Relay working for the fan?

[Dre5gtt]

Centre vents are cold air vents. Is the rad getting hot? Bridge the plug for the rad fan switch does that come on. Relay working for the fan?

Sorted now air in the system tried the old blow down the header tank and used the screws by the water pump