I found out something realy strange tonight I removed my aircon and my fan used to run constant so I bridged the connector and my fan stopped.
But now when I put my heater fan on my radiator fan comes on!
You removed the pressure switch on the PSF corner when you were removing the pipes. Retrieve it from the old pipes and plug it back into the connector. You should tuck it up out of the way to stop it rattling about. Your cooling fan will operate properly again now.