Air fan all time On, I can not turn it Off. The fan runs at Mid level and goes to High when set by control.

I have located two relays one that allows to switch the Fan to High speed the other is beside the fuses.
When the relay that alows switching to High was removed the fans still continued to run at Mid level but can't switch to High.
When the relay beside the fuses was removed the Fan did not work. I have switched this relay with other of same type but as soon as I connected a relay the Fan came on again.

Thank you for your help.